Green’s Dictionary of Slang

wad n.3

[SE wad, a plug that holds in the powder in a cartridge]

[late 19C+] semen, esp. an ejaculation of semen; thus wadbuster n., an extra-vigorous ejaculation.

In compounds

wad-waste (n.)

[1960s] a term of abuse.

In phrases

blow one’s wad (v.)

1. [1970s+] to indicate surprise or excitement .

2. [1990s+] to speak one’s mind.

3. [2000s] to ejaculate.

pop one’s wad (v.)

[1970s] (US) of a man, to achieve orgasm.

shoot one’s wad (v.)

1. [mid-19C+] (US, also shoot the wad) to commit or bet everything one has, to say all one has to say [wad n.1 (1)].

2. [late 19C+] (orig. US) to exhaust oneself, or one’s possibilities; to speak out forcefully and finally .

3. [late 19C+] (orig. US, also shoot a wad) to ejaculate.

4. [1960s+] (US) to break down emotionally.