Green’s Dictionary of Slang

lime n.2

[lime v.]

(orig. W.I.) a spontaneous, unorganized social gathering, usu. of young people. Often qualified by its focus, e.g. beach lime, a beach get-together; a roti lime, a gathering to eat roti; thus punning phr. this lime has no juice, this get-together is boring.

[WI]cited in Allsopp Dict. Carib. Eng. Usage (1996).

In phrases

coast (a) lime (v.)

(W.I./UK black) to hang around chatting and socializing.

[WI]S. Selvon Lonely Londoners 55: A allnight cafe in the gate where Cap does always hang out, coasting lime over a cuppa or a cup of coffee. [Ibid.] 121: If you start to live again you coast a lime by the Serpentine and go for a row on the river.