(v. t.) To strengthen again; to fortify anew.

accelerate aggrandize aggravate augment blow up boost brace brace up buttress case harden complicate concentrate condense confirm consolidate deepen double enhance enlarge exacerbate exaggerate expand extend fortify gird harden heat up heighten hop up hot up intensify invigorate jazz up key up magnify make complex multiply nerve prop ramify redouble refresh reinforce reinvigorate restrengthen sharpen shore up soup up steel step up stiffen strengthen support sustain temper toughen triple undergird whet