Green’s Dictionary of Slang

holer n.

also hole-monger
[hole n.1 (1b) + SE sfx -monger; note 13C–15C SE holour, a fornicator or whoremonger and, as such, applied to men only]

1. a womanizer, a successful seducer.

[UK]Partridge DSUE (1984) 561: C.16–20.

2. a male prostitute.

[UK]Farmer & Henley Sl. and Its Analogues.

3. a pimp.

[UK]Farmer & Henley Sl. and Its Analogues.

4. a prostitute.

[UK]Farmer & Henley Sl. and Its Analogues.