1. (v. t.) 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.

2. (v. i.) To grow wide or wider; to enlarge; to spread; to extend.

accrue accumulate add to advance aggrandize amplify appreciate augment balloon bloat blow up boom branch branch out breed broaden build build up bulk bulk out crescendo deal in generalities deepen deploy develop dilate disperse distend ecumenicize enlarge expand extend fan fan out fill out flare gain gain strength generalize get ahead globalize go up greaten grow hike hike up huff increase inflate intensify magnify make a generalization mount multiply open open up outspread outstretch overgrow overrun proliferate puff puff up pump pump up raise ramify rarefy rise run up shoot up snowball splay spraddle sprangle sprawl spread spread like wildfire spread out strengthen stretch sufflate swell tumefy unfold universalize up wax