lengthen

/ˈleŋ(k)-thən/

verb

  1. to make longer

  2. to grow longer

extend lengthen prolong protract mean to draw out or add to so as to increase in length. extend and lengthen imply a drawing out in space or time but extend may also imply increase in width, scope, area, or range. prolong suggests chiefly increase in duration especially beyond usual limits.