WordNet (r) 3.0 (2006):

refreshen
    v 1: become or make oneself fresh again; "She freshened up after
         the tennis game" [syn: freshen, refresh, refreshen,
         freshen up]
    2: make fresh again [syn: refresh, freshen, refreshen]
       [ant: fag, fag out, fatigue, jade, outwear, tire,
       tire out, wear, wear down, wear out, wear upon,
       weary]