Green’s Dictionary of Slang

get it v.

1. [early 19C] to be assaulted or beaten up.

2. [mid-19C+] (US) to be shot, wounded or killed.

3. [mid-19C+] to be punished or reprimanded.

4. [late 19C+] to be subjected to abuse or nagging.

5. [1930s+] of a man, to have sexual intercourse; of a woman, to be subjected to intercourse.

6. [1940s] to catch a venereal disease.

7. [1940s+] (US) to go at great speed.

8. [1960s+] (US) to be pleasing, attractive; used in negative contexts, e.g. Sorry, but he just doesn’t get it.

In phrases

get it all (v.)

[1900s] (US Und.) to get life imprisonment.

get it down (v.)

[1990s+] (US) to master, e.g. a job of work.

get it in one (v.)

[1930s+] to succeed in doing, in understanding etc. at the first try, esp. in a sexual context.

get it in the neck (v.)

see separate entry.

get it off (v.) (also get ’em off, get one off) [get off v.2 ]

[1930s+] (US) to reach orgasm, to copulate, to derive pleasure.

get it off with (v.) [var. on have it off v.]

[1970s+] of a man, to have sexual intercourse.

get it on

see separate entries.

get it up/get it up for (v.)

see separate entries.

get it where Maggie wore the beads (v.) [i.e. get it in the neck v. (1)]

[late 19C-1910s] to be hit or hurt, to suffer in the worst place, or fig. in the worst poss. way given the context.

get it where the chicken got the axe (v.) [i.e. get it in the neck v. (1)]

[late 19C–1910s] to suffer in the worst possible way, according to context.