Source : Webster's Revised Unabridged Dictionary (1913)

Widen \Wid"en\, v. t. [imp. & p. p. {Widened}; p. pr. & vb. n.
   {Widening}.]
   To make wide or wider; to extend in breadth; to increase the
   width of; as, to widen a field; to widen a breach; to widen a
   stocking.

Widen \Wid"en\, v. i.
   To grow wide or wider; to enlarge; to spread; to extend.

         Arches widen, and long aisles extend.    --Pope.

Source : WordNet®

widen
     v 1: become broader or wider or more extensive; "The road
          widened" [ant: {narrow}]
     2: make (clothes) larger; "Let out that dress--I gained a lot
        of weight" [syn: {let out}] [ant: {take in}]
     3: make wider; "widen the road"
     4: extend in scope or range or area; "The law was extended to
        all citizens"; "widen the range of applications"; "broaden
        your horizon"; "Extend your backyard" [syn: {broaden}, {extend}]