firm up

To make plans or arrangements clearer and more certain.

• Let us firm up our plans.
• We firmed up the dates yesterday.
• Can you firm those arrangements up before Friday?

How to use it: firm up something (We need to firm up the travel dates.); firm something up (Let us firm the details up tomorrow.)

Similar words: finalize, confirm, settle

Common phrases: firm up plans, firm up details, firm something up

To become less soft or liquid and more solid.

• Let the jelly firm up.
• The chocolate firmed up as it cooled.
• Put the mixture in the fridge until it firms up.

Similar words: set, harden, solidify

Opposites: soften

Common phrases: jelly firm up, mixture firm up, butter firm up

To become clearer and more certain, especially when talking about plans.

• Our plans should firm up soon.
• The dates firmed up after the meeting.
• Tell me when your travel arrangements firm up.

Similar words: take shape, become definite

Common phrases: plans firm up, details firm up, arrangements firm up

To make muscles stronger and less soft through exercise.

• These exercises firm up your legs.
• She firmed up her arms by lifting weights.
• Can swimming help firm up my stomach?

How to use it: firm up something (These exercises help firm up your stomach.); firm something up (Regular workouts will firm your arms up.)

Similar words: tone, strengthen

Common phrases: firm up muscles, firm up arms, firm something up

To become stronger and less soft through exercise.

• Your muscles will firm up.
• Her legs firmed up after months of cycling.
• My arms are starting to firm up with regular exercise.

Similar words: tone up, strengthen

Common phrases: muscles firm up, arms firm up, legs firm up