From The Collaborative International Dictionary of English v.0.48:
committed \committed\ adj.
1. Bound or obligated, as under a pledge to a particular
cause, action, or attitude. Opposite of uncommitted.
Note: [Narrower terms: bound up, involved, wrapped up;
dedicated, devoted; pledged, sworn]
[WordNet 1.5]
2. Associated in an exclusive sexual relationship; also
called attached. Opposite of unattached.
Note: [Narrower terms: affianced, bespoken, betrothed,
engaged, pledged, promised(predicate); married]
[Also See: loving.]
Syn: attached.
[WordNet 1.5]
3. Consigned involuntarily to custody, as in a prison or
mental institution.
[WordNet 1.5]
From The Collaborative International Dictionary of English v.0.48:
Pledge \Pledge\, v. t. [imp. & p. p. Pledged; p. pr. & vb. n.
Pledging.] [Cf. OF. pleiger to give security. See Pledge,
n.]
1. To deposit, as a chattel, in pledge or pawn; to leave in
possession of another as security; as, to pledge one's
watch.
[1913 Webster]
2. To give or pass as a security; to guarantee; to engage; to
plight; as, to pledge one's word and honor.
[1913 Webster]
We mutually pledge to each other our lives, our
fortunes, and our sacred honor. --The
Declaration of
Independence.
[1913 Webster]
3. To secure performance of, as by a pledge. [Obs.]
[1913 Webster]
To pledge my vow, I give my hand. --Shak.
[1913 Webster]
4. To bind or engage by promise or declaration; to engage
solemnly; as, to pledge one's self.
[1913 Webster]
5. To invite another to drink, by drinking of the cup first,
and then handing it to him, as a pledge of good will;
hence, to drink the health of; to toast.
[1913 Webster]
Pledge me, my friend, and drink till thou be'st
wise. --Cowley.
[1913 Webster]