Green’s Dictionary of Slang

clout n.2

[ety. unknown; ? link to SE clout, a cloth, thus a ‘lump’ of material, thus any sort of lump; or link to SE clod. Note WWI Aus. milit. clout, a wound. Earlier use of sense 1 was SE]

1. [16C+] a heavy blow; as the clouts, a heavy beating.

2. [1960s–70s] aggression, power.

In phrases

give someone the clouts (v.)

[1910s] to hit, to beat up.