Green’s Dictionary of Slang

1. (also blit) the vagina.

1997		Roger’s Profanisaurus in Viz 87 Dec. n.p.: blit n. See blart.
1999		Guardian Sport 16 Apr. 16: We footballers are [...] numero uno in the blart magnet stakes.

2. a generic for women, considered as sexual objects.

1997

Roger’s Profanisaurus in Viz 87 Dec. n.p.: blart n. Female vagina. Also collective n. Women; totty (qv). e.g. ‘Golly gosh! This pub is heaving with blart’.