Green’s Dictionary of Slang

1. to mark down.

1899

C. Rook Hooligan Nights 47: There’s a ’ouse that I’ve ’ad waxed for about a week down Denmark Hill way.

2. (UK Und.) to remember clearly.

1906

E. Pugh Spoilers 256: She’d got him waxed. ’It ’im off to me, she did, like a photograph.