Phrasal Verbsphrasal verbjump to other results
firm upphrasal verb
to become harder or more solid Put the mixture somewhere cool to firm up.jump to other results
- 1to make arrangements more final and fixed The company has not yet firmed up its plans for expansion. The precise details still have to be firmed up.
- 2 to make something harder or more solid A few weeks of Pilates will firm up that flabby stomach.