WordNet (r) 3.0 (2006):

circularize
    v 1: canvass by distributing letters [syn: circularize,
         circularise]
    2: canvass by using a questionnaire
    3: distribute circulars to [syn: circularize, circularise]
    4: cause to become widely known; "spread information";
       "circulate a rumor"; "broadcast the news" [syn: circulate,
       circularize, circularise, distribute, disseminate,
       propagate, broadcast, spread, diffuse, disperse,
       pass around]
    5: make circular