Green’s Dictionary of Slang

1. (Aus.) to tolerate, to put up with.

1915		C.J. Dennis ‘The Intro’ in Songs of a Sentimental Bloke 22: I reckerlect I arst ter be ’er friend; / An’ tried ter play at ’andies in the park, / A thing she wouldn’t sight. Aw, it’s a nark!
1963		R. McGregor-Hastie Compleat Migrant 108: Sight a ratbag: to put up with someone you dislike.

2. (UK Und./UK black) to observe, to see.

1972		‘Rawbone Malong’ Ah Big Yaws? 40: ‘I’ll see you’ has become [...] ‘I’ll sight you’. As in [...] A: ‘Wyell, Ahm gohnnow.’ B: ‘Arc Ay. Sart chew oh.’.
1999		(con. 1979–80) A. Wheatle Brixton Rock (2004) 37: Sight you later.
2001		(con. 1981) A. Wheatle East of Acre Lane 64: We ’ave to step so we’ll sight you later.