The Jargon File (version 4.4.7, 29 Dec 2003):

chawmp
 n.

    [University of Florida] 16 or 18 bits (half of a machine word). This term
    was used by FORTH hackers during the late 1970s/early 1980s; it is said to
    have been archaic then, and may now be obsolete. It was coined in revolt
    against the promiscuous use of ?word? for anything between 16 and 32 bits;
    ?word? has an additional special meaning for FORTH hacks that made the
    overloading intolerable. For similar reasons, /gaw'bl/ (spelled ?gawble? or
    possibly ?gawbul?) was in use as a term for 32 or 48 bits (presumably a
    full machine word, but our sources are unclear on this). These terms are
    more easily understood if one thinks of them as faithful phonetic spellings
    of ?chomp? and ?gobble? pronounced in a Florida or other Southern U.S.
    dialect. For general discussion of similar terms, see nybble.