ret·i·cent 
(rĕtĭ-sənt)
(rĕtĭ-sənt)adj.
1. Inclined to keep one's thoughts, feelings, and personal affairs to oneself. See Synonyms at laconic.
2. Restrained or reserved: "The laughter was steady, if reticent" (Bernard Lown).
3. Usage Problem Reluctant; unwilling.
[Latin reticēns, reticent-, present participle of reticēre, to keep silent : re-, re- + tacēre, to be silent.]
reti·cence (-səns) adv.
reti·cent·ly adv.
Usage Note: Reticent is generally used to indicate a reluctance to speak. Most commentators on usage have criticized its extended use as an all-purpose synonym for reluctant. In our 2001 survey, 83 percent of the Panel found unacceptable the sentence A lot of out-of-towners are reticent to come to the Twin Cities for a ballgame if there's a chance the game will be rained out.