Source : Webster's Revised Unabridged Dictionary (1913)

Unfrequent \Un*fre"quent\, a. [Pref. un- not + frequent.]
   Infrequent. --J. H. Newman. -- {Un*fre"quent*ly} adv.

Unfrequent \Un`fre*quent"\, v. t. [1st pref. un- + frequent.]
   To cease to frequent. [Obs.]

         They quit their thefts and unfrequent the fields. --J.
                                                  Philips.