Phrasal Verbs with DROP

drop back
to return to a lower level, value, price, etc.
Prices could drop back by up to 10 percent.

drop by
to visit someone informally
He dropped by my office this morning.

drop off
to take someone by car to a particular place
I can drop you off on my way home.

drop out
to leave school, college, etc. without finishing your studies
He dropped out of college after one semester.

drop out
stop participating or being involved in something
He decided to drop out of active politics.