What is Sodomy?

Legal Definition
Sodomy (/ˈsɒdəmi/) is generally anal or oral sex between people or sexual activity between a person and a non-human animal (bestiality), but it may also mean any non-procreative sexual activity. Originally, the term sodomy, which is derived from the story of Sodom and Gomorrah in chapters 18 and 19 of the Book of Genesis in the Bible, was commonly restricted to anal sex. Sodomy laws in many countries criminalized these behaviors, and other disfavored sexual activities as well. In the Western world, many of these laws have been overturned or are not routinely enforced.
-- Wikipedia
Legal Definition
Crim. law. The crime against nature, committed either with man or beast.

2. It is a crime not it to be named; peccatum illud horrible, inter christianos non nominandum. 4 Bl. Com. 215; 1 East, P. C. 480, 487; Bac. Ab. h. t.; Hawk. b. 1, c. 4; 1 Hale, 669; Com. Dig. Justices, S 4; Russ. & Ry. 331.

3. This crime was punished with great severity by the civil law. Nov. 141; Nov. 77; Inst. 4, 18, 4. See 1 Russ. on Cr. 568; R. & R. C. C. 331, 412; 1 East, P. C. 437.
-- Bouviers Law Dictionary
Legal Definition
In criminal law. The crime of unnatural sexual connection; so named from its prevalence in Sodoin. See Genesis, xix. This term is often defined in stafutes and judicial decisions as meaning "the crime against nature," the "crimen innominatum," or as carnal copulation, against the order of nature, by man with man, or, in the same unnatural manner, with woman or with a beast. See Or. Code Ga. § 4352 ; Honselman v. People, 168 111. 172, 48 N. E. 304. But, strictly speaking, it should be used only as equivalent to "pederasty," that is, the sexual act as performed by a man upon the person of another man or a boy by penetration of the anus. See Ausman v. Veal, 10 Ind. 355, 71 Am. Dec. 331. The term might also, without any great violence to ita original meaning, be so extended as to cover the same act when performed in the same manner by a man upon the person of a woman. Another possible method of unilateral sexual connection, by penetration of the mouth (penem in orem alii immittere, vel penem alii in orem recipere) is not properly called "sodomy," but "fellation." That this does not constitute sodomy within the meaning of a statute is held in Harvey v. State, 55 Tex Cr. App. 199, 115 S. W. 1198 ; Com. v. Poindexter (Ky.) 118 S. W. 943 ; Lewis v. State, 36 Tex. Cr. R. 37, 35 S. W. 372, 61 Am. St. Ren. 831. On the other hand 'bestiality is the carnal copulation of a human being with a brute, or animal of the sub-human orders, of the opposite sex. It is not identical with sodomy, nor is it a form of sodomy, though the two terms are often confused in legal writings and sometimes in statutes. See Ausman v. Veal, 10 Ind. 355, 71 Am. Dec. 33l. Bucgery is a term rarely used in statutes, but apparently including both sodomy ,tn the widest sense) and bestiality as above defined. See Ausman v. Veal, 10 Ind. 355, 71 Am. Dec. 331; Com. v. J., 21 Pa. Co. Ct R. 625.
-- Black's Law Dictionary
Legal Definition
Connection per anum between two human beings of male sex. See 10 Ind. 355, 71 Am. Dec. 331.
-- Ballentine's Law Dictionary