Outside of law, the term has a more generic meaning, including not only acts but attraction or sexual inclination.
Traditionally, the law in regards to homosexuality, or those practising it, homosexuals, has focussed on sodomy as the crime; not "homosexuality". Indeed, the term homosexuality did not develop until "the late 19th century" (see Lawrence below).
In 1986, the US Supreme Court, in Bowers v Hardwick 478 US 186, wrote:
“Prescriptions against sodomy have very ancient roots. Decisions of individuals relating to homosexual conduct have been subject to state intervention throughout the history of Western civilization. Condemnation of those practices is firmly rooted in Judeao-Christian moral and ethical standards. Homosexual sodomy was a capital crime under Roman law. During the English Reformation when powers of the ecclesiastical courts were transferred to the King's Courts, the first English statute criminalizing sodomy was passed. Blackstone described “the infamous crime against nature” as an offense of “deeper malignity” than rape, a heinous act “the very mention of which is a disgrace to human nature,” and “a crime not fit to be named.”
The 2003 Lawrence v Texas 519 US 558 decision of the US Supreme Court was a significant case. In it, the Court sought to clarify the record as regards to historical treatment of homosexuality:
“There is no longstanding history in this country of laws directed at homosexual conduct as a distinct matter. Beginning in colonial times there were prohibitions of sodomy derived from the English criminal laws passed in the first instance by the Reformation Parliament of 1533.
"The English prohibition was understood to include relations between men and women as well as relations between men and men. Nineteenth-century commentators similarly read American sodomy, buggery, and crime-against-nature statutes as criminalizing certain relations between men and women and between men and men.
"The absence of legal prohibitions focusing on homosexual conduct may be explained in part by noting that according to some scholars the concept of the homosexual as a distinct category of person did not emerge until the late 19th century. Thus early American sodomy laws were not directed at homosexuals as such but instead sought to prohibit nonprocreative sexual activity more generally. This does not suggest approval of homosexual conduct (but) it does tend to show that this particular form of conduct was not thought of as a separate category from like conduct between heterosexual persons.
"Instead of targeting relations between consenting adults in private, 19th-century sodomy prosecutions typically involved relations between men and minor girls or minor boys, relations between adults involving force, relations between adults implicating disparity in status, or relations between men and animals.
"To the extent that there were any prosecutions for the acts in question, 19th-century evidence rules imposed a burden that would make a conviction more difficult to obtain even taking into account the problems always inherent in prosecuting consensual acts committed in private. Under then-prevailing standards, a man could not be convicted of sodomy based upon testimony of a consenting partner, because the partner was considered an accomplice. A partner's testimony, however, was admissible if he or she had not consented to the act or was a minor, and therefore incapable of consent. The rule may explain in part the infrequency of these prosecutions."
“It was not until the 1970's that any State singled out same-sex relations for criminal prosecution, and only nine States have done so.”
In the early 1900s, the law embraced homosexuality as a medical condition. An extract from a US Senate document of the era uses this language:
“Classes of mentally defectives should be enlarged to include homosexuals and other sex perverts."
As late as 1967, American immigration law tended towards the exclusion of persons with "psychopathic personality" (Boutilier v Immigration and Naturalization Service 187 US 118).
As late as 2003, the Texas Penal Code provided:
“A person commits an offense if he engages in deviate sexual intercourse with another individual of the same sex" and "deviate sexual intercourse (includes) any contact between any part of the genitals of one person and the mouth or anus of another person; or the penetration of the genitals or the anus of another person with an object."
In 1968, Canada's then-Prime Minister Pierre Trudeau, to justify his new law decriminalizing homosexuality, said:
"There's no place for the state in the bedrooms of the nation."