widen

verb5

1. •
   To become wide or wider.

   • His eyes widened as her negligee fell to the floor.
2. •
   To make wide or wider.

   • The widening works include the rebuilding of the skew bridge near Northwood to take four tracks, and to enable the Rickmansworth Road to be widened to 60 ft.; […]. — 1959
3. •
   To let out clothes to a larger size.

   • She widened his trousers for him.
4. •
   To broaden or extend in scope or range.

   • The police widened their enquiries.
5. •
   To convert to a data type that can hold a larger number of distinct values.