jelly bean n.
1. a person who is ‘sweet’ or ‘soft’.
(a) [1910s–60s] (US) a sweetheart.
(b) [1910s+] (US) a foolish, inept, dishonest or effeminate person.
(c) [1920s–30s] one who is devoted to pleasure rather than work; esp. used of a high-school student.
(d) [1920s–30s] a fashionably dressed young man, a womanizer.
2. [1930s+] a pimp.
3. [1960s] (US gay) a small penis.
4. [1960s+] (US black) a term of address.
5. in drug uses [the drugs resemble sweets].
(a) [1960s+] (drugs) any form of pill, e.g. a barbiturate, an amphetamine.
(b) [1990s+] (US campus) a painkiller.
(c) [1990s+] (drugs) crack cocaine.
see it must be jelly, ’cause jam don’t shake like that under jelly n.1