Green’s Dictionary of Slang

rack n.1

[Irish raca, a comb]
(Irish)

1. coarse hair.

[Ire]Share Slanguage.

2. a comb.

[Dublin Dly Exp. 18 Apr. 2/6: [advert] The Hair Brush 1s 6d. The Rack Comb 1s].
[Ire]P.W. Joyce Eng. As We Speak It In Ireland.