Green’s Dictionary of Slang

shag n.1

[shag v.1 (1)]

1. [late 18C+] (also shagg) an act of sexual intercourse.

2. [1930s] (US teen) a party where pre-adolescents experiment sexually.

3. [1940s–60s] a person, in general use.

4. [1960s+] a person, usu. a woman but in 1990s+ also a man, seen simply as a sexual object; thus good shag, lousy shag.

In compounds

shag all (n.) [var. on fuck all n.]

[1970s+] nothing at all.

shag artist (n.) [artist n. (1)]

[1960s+] a womanizer, a sexual athlete.

shag-bag (n.) [SE bag]

1. [1970s] (orig. milit.) a prostitute.

2. [1990s+] (orig. Aus.) a general pej. term for a woman; sexual availability is presumed, but not automatic.

3. [2000s] (US) the vagina.

shag-pad (n.) [pad n.2 (2)]

[2000s] an apartment or room where one can bring a casual sex partner.

shag-wagon (n.) (also shagging station, ...wagon)

[1960s+] a van or car used primarily for sex.