mug up

verb — 2 senses

mug up

verb

1

Slang To study intensely.

I mugged up on the meaning of road signs before taking my driving test.
You need to mug up Tennyson for this class.

2

Entertainment, Lifestyle, Theater Obsolete, Slang To paint one's face or put on a costume for the purpose of impersonation.

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.