Meaning of “unscrew” - Learner’s Dictionary

unscrew

verb [ T ] us uk /ʌnˈskruː/
TWIST

to remove something by twisting it:

I can't unscrew the lid.
REMOVE METAL PIECES

to remove something by taking the screws (= small, metal pieces) out of it

(Definition of “unscrew” from the Cambridge Learner’s Dictionary © Cambridge University Press)