Green’s Dictionary of Slang

1. to loiter, to ‘hang around’.

1909		J. Ware Passing Eng. of the Victorian Era 34/2: Block a quiet pub (Peoples’). To stop a long time in a tavern.
2016		A. Wheatle Crongton Knights 258: ‘We’ll go with you up to your yard [...] And I don’t care if we have to block there for the rest of the night’.

2. (US prison) to watch.

1918

H. Simon ‘Prison Dict.’ in AS VIII:3 (1933) 24/1: BLOCK. Watch.

3. (Aus.) to deceive, to get the better of.

1984

Partridge DSUE (8th edn) 96/2: since ca. 1930.

4. (Aus.) to stop talking as instructed.

1996

B. Scott Banshee and Bullocky 29: ‘Ah, get blocked, yer whingein’ blanks, or I’ll job yers’ [...] which shut them up.