From WordNet (r) 2.0 (August 2003) [wn]:
bailiwick
n 1: the area over which a bailiff has jurisdiction
2: a branch of knowledge; "in what discipline is his
doctorate?"; "teachers should be well trained in their
subject"; "anthropology is the study of human beings"
[syn: discipline, subject, subject area, {subject
field}, field, field of study, study, {branch of
knowledge}]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Bailiwick \Bail"i*wick\, n. [Bailie, bailiff + wick a village.]
(Law)
The precincts within which a bailiff has jurisdiction; the
limits of a bailiff's authority.
[1913 Webster]