The word sexuality is first recorded in English at the end of 18c. It is an abstract noun formed on the adjective sexual, probably on the model of post-classical Latin sexualitas. This Latin word was probably also coined not earlier than the second half of 18c, and, although it may not actually have been used by the great Swedish naturalist Linnaeus, it occurs early with reference to his work on biology, and especially botany. The corresponding English sense is defined by the OED as ‘The quality of being sexual or possessing sex. Opposed to asexuality n.’ The earliest example for this sense comes from the third edition of John Walker’s Elements of geography, and of natural and civil history (1797): “The Linnaean system..is founded on the sexuality of plants.” This sense has remained in use by biologists ever since; the areas of contestation and ambiguity in the word’s contemporary use stem from its application to humans.
The earliest sense in OED used in reference to humans is attested in 1833, and defined as: ‘Sexual nature, instinct, or feelings; the possession or expression of these.’ Sexuality as so defined is something usually assumed to be inherent in all normally functioning human beings, although usage differs considerably according to the user’s standpoint on a number of social and cultural issues. This sense has long been found in general as well as technical use; OED’s earliest example is from a collection of traditional tales from Scotland, A. Picken’s Traditionary Stories Old Families (1833): “This, like most matters of love and sexuality, became the bitter bottoming of many sorrows.”
Before looking at this sense in further detail, the second major sense of sexuality as applied to human beings should be considered. This sense is first attested in 1897, and is defined in OED as ‘a person's sexual identity in relation to the gender to which he or she is typically attracted; the fact of being heterosexual, homosexual, or bisexual; sexual orientation.’ This use probably arose on the model of the words homosexuality and heterosexuality. It is not common in the first half of 20c, and appears to have taken some time to break through into non-technical use. However, a use with this meaning in a New York Times book review from 1958, quoted by OED, points towards a characteristic pattern of contemporary usage: “Torn between his love for an intelligent, sympathetic French girl, Solange, and a haunting attraction to his top sergeant… he is held captive by… a brutal reality demanding that he define his own sexuality or face damnation.”
Corpus data for contemporary English shows that (by a considerable margin) the two most frequent collocations of sexuality are (i) human sexuality and (ii) use modified by a possessive pronoun, e.g. their sexuality, his sexuality, my sexuality. The collocation human sexuality correlates closely with the meaning defined as ‘Sexual nature, instinct, or feelings; the possession or expression of these’. The word is used with this meaning by people with a wide variety of different social, political, moral, and religious standpoints, and these differing standpoints will affect how different individuals conceptualize human sexuality. The term labels a concept that is at the centre of a key battlefield in contemporary social and cultural debate. However, the mapping between word and concept is itself relatively uncomplicated: what is at issue is how different individuals define or conceptualize ‘sexual nature, instinct, or feelings’, as well as, crucially, what they take to be ‘normal’, ‘natural’, or part of the expected or accepted spectrum of human feelings and behaviour.
In the case of use modified by a possessive pronoun, e.g. their sexuality, his sexuality, my sexuality, use of the word sexuality may map to either of OED’s main senses, ‘Sexual nature, instinct, or feelings; the possession or expression of these’ or ‘A person's sexual identity in relation to the gender to which he or she is typically attracted; the fact of being heterosexual, homosexual, or bisexual; sexual orientation.’ However, there is an interesting tension between these uses. When used in the second meaning, the construction typically refers to a particular sexual identity to which a person is (usually) taken to belong categorically; uses typically refer to recognition, suppression, repression, or acceptance of one’s sexuality. Overwhelmingly, usage refers to homosexuality: if a man is described as “hiding his sexuality”, this nearly always means that he is hiding the fact that he is gay (however this is construed), not that he is hiding his heterosexuality.
But alongside this usage, sexuality modified by a possessive pronoun is also used frequently in the meaning ‘sexual nature, instinct, or feelings’. Searching Google Books shows that, for instance, “he/she [struggles/attempts/ is obliged/is forced/is expected] to suppress/repress his/her sexuality” is found frequently in reference to gay people who attempt to “suppress” their sexual identity, but also not uncommonly in reference to heterosexual men who attempt to “suppress” or “control” their sexual instincts in a particular behavioural situation. Such uses are often, but not always, from contexts with clear echoes of psychoanalytical discourse, e.g.: “Early on, he had learned to repress his sexuality in response to his rejecting wife” (from Anne C. Heller’s Ayn Rand );or (from A. Gural-Migdal and R.Singer’s Zola and Film ), “Eugène Rougon..attempts to repress his sexuality by finding other means of powerful sexual sublimation. He thus achieves the pinnacle of success...by avoiding the charms of a femme fatale”; or again (from A. J. Solnit, P. Neubauer and S. Abrams’s The Psychoanalytic Study of the Child ), “Meyers (1996) suggested that even though the Frosts had many children, Elinor was a reluctant sexual partner and that Frost had to suppress his sexuality.” Logically, this construction should also be found with reference to homosexual men attempting to suppress their sexual instincts in a particular behavioural situation. But perhaps in that context the risk of ambiguity is too great to allow this use to occur with any frequency; use in this meaning with reference to women, whether gay or straight, is also much less common.
Individuals (or perhaps, different individuals) are thus conceptualized as possessing a sexuality in two distinct meanings: one is a categorical matter of group membership (heterosexual, homosexual, bisexual); the other a question of each individual’s feelings or instincts and how these affect behaviour. The expression sexual orientation exists as a synonym in the first meaning, but sexuality appears to be the term preferred by many (perhaps because of connotations it carries of an inherent, non-volitional quality). In the second meaning, sexual instinct is perhaps the likeliest substitute, but occurs only relatively rarely. Coexistence of the two meanings in parallel constructions is surprising, since the danger of ambiguity is real and the meanings occur in a semantic area that is generally regarded as highly sensitive, where ambiguity may lead to intense embarrassment or social difficulties. Whether the two meanings continue to co-exist, and continue to occur in such similar constructions, may be revealing about changing social attitudes in coming decades.