Meaning of “themselves” - Learner’s Dictionary

themselves

pronoun uk us /ðəmˈselvz/
REFLEXIVE

A2 the reflexive form of the pronoun 'they':

They're both 16 - they're old enough to look after themselves.
EMPHASIS

B2 used to emphasize the pronoun 'they' or the particular group of people you are referring to:

The staff themselves were unhappy with the decision.
They've decided to run the club themselves.
(all) by themselves

A2 alone or without anyone else's help:

The kids arranged the party all by themselves.
(all) to themselves

for their use only:

They had the whole campsite to themselves.

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