Green’s Dictionary of Slang

rant v.

[ramp v.2 (1)]

to take by violence.

Walford’s Antiquarian Ap. 253: To rant is to appropriate anything in a forcible manner. ‘Lets go and rant their marleys,’ says one urchin to another, and straightway the pair annex the possessions of a more respectable party. But it is also used to denote undue freedom with females, and springs, no doubt, from rantipole [F&H].