1. [early 19C+] five shillings (25p), a five-shilling coin (see cite 1910); obs. outside films, books etc. of a pre-metric era; thus half a dollar, 2s 6d [under the 1817–1931 gold standard £1 sterling was worth US$4].
2. [late 19C] (S.Afr.) 1s 6d.
3. [late 19C; 1980s+] money; usu. in pl.
4. [1960s+] (US black/Und.) $100; $100 worth of drugs.
SE in slang uses
[1960s+] (US gay) a male prostitute who claims that his penis is so large that even charging by the inch he could still get rich.
[late 19C] (US Und.) a store that displayed valuable articles priced at one dollar in order to attract customers, who were then subjected to a variety of ‘short-con’ tricks.
[1930s–40s] (US) a cheap prostitute.