Source : Webster's Revised Unabridged Dictionary (1913)

Unwise \Un*wise"\, a. [AS. unw[=i]s. See {Un-} not, and {Wise},
   a.]
   Not wise; defective in wisdom; injudicious; indiscreet;
   foolish; as, an unwise man; unwise kings; unwise measures.

Source : WordNet®

unwise
     adj 1: showing or resulting from lack of judgment or wisdom; "an
            unwise investor is soon impoverished"
     2: not appropriate to the purpose [syn: {inexpedient}]