1. [late 17C+] (also chumbuddy) a close friend, a room-mate [mid-19C+ use is SE, although Hotten (1859) includes it since it is ‘in such frequent use with the lower orders that it demanded a place in this glossary’].
2. [late 18C–19C] (UK Und.) a fellow-prisoner.
3. [mid-19C+] (also chummy) a term of friendly address.
4. [late 19C] the vagina [i.e. the ‘friend’ of the penis].
5. [1990s+] (UK juv., also chum boy, chummer) a male homosexual.
6. see new chum n.
[early–mid-19C] (UK prison) an official responsible for allotting prisoners to cells, on payment of a fee.
[early–mid-19C] (UK prison) a paper that on payment of a fee gives a new prisoner the right of a place in a cell.
[mid-19C+] a veteran.