Meaning of “perm” - Learner’s Dictionary

perm

noun [ C ] uk us /pɜːm/

the use of chemicals on someone's hair to make it have curls for several months, or the hairstyle that is made in this way:

I'm thinking of having a perm.
perm verb [ T ]

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