Green’s Dictionary of Slang

soak v.1

1. in context of alcohol.

(a) [17C+] (also soak up) to drink heavily.

(b) [19C] to ply with liquor.

(c) [1900s] to spend money on drink.

2. in monetary senses.

(a) [mid-19C–1920s] to pawn; to give as collateral.

(b) [1900s–40s] (US campus) to borrow [one leaves one’s possession ‘to soak’].

(c) [1900s] (US) to put away.

3. see let it soak

In derivatives

soaky (adj.)

[mid-19C] very drunk.

In phrases

in soak

1. [mid–late 19C] in prison.

2. [mid-19C+] in pawn; thus soak n., pawn, a pawnshop; thus antonym out of soak.

3. [late 19C] (Aus.) drunk.

SE in slang uses

In phrases

let it soak (v.) (also lie in soak, soak)

[late 19C+] of a man, to linger before withdrawing one’s penis after intercourse.

soak one’s face (v.) [SE face]

[late 18C+] to drink, to quench one’s thirst.

soak the mill (v.) [SE mill, used as generic for one’s property]

[late 19C] (US) to drink away one’s possessions.

In exclamations

go soak your head! (also go soap your ear!)

[mid–19C+] an abusive, dismissive remark.