Reverse.
Back something up.
Quit a class, school, etc.
Drop out.
Wear something a few times so it doesn't look/feel new.
Break something in.
Remove with something sharp.
Cut something off.
Stop functioning (vehicle, machine).
Break down.
Add air.
Blow something up.
(of hair, teeth) Become loose and unattached.
Fall out.
Develop a skin condition.
Break out in something.
Sign out of a website.
Log off.
Divide into smaller parts.
Break something down.
Bring somebody up.
Understand, find the answer.
Arrive and register at a hotel or airport.
Check in.
Start to fly.
Take off.
Make unhappy.
Bring someone down.
Get to the same point as somebody else.
Catch up.
Discover.
Find out.
Help.
Chip in.
Remove clothing.
Take something off.
Become sick.
Come down with something.
Become happier.
Cheer up.
Leave home to go on a social event.
Go out.
Reluctantly stop fighting or arguing.
Give in.
Stop the energy flow, switch off.
Turn something off.
Insult, make somebody feel stupid.
Put somebody down.