Green’s Dictionary of Slang

lively, noisy, energetic; ‘on the ball’.

1957		A. La Guma ‘Nocturne’ in Malan (1994) 18: Classical stuff. Just a helluva noise. Give me a wakker jol anytime.
2005		A. Lovejoy Acid Alex 211: The hawks will come to you and offer a cigarette, a cup of tea, a biscuit – maybe even a joint! Everything you accept from a hawk is a transaction. [...] Do I need to paint a picture? You have to be wakker.