Meaning of “subject” - Learner’s Dictionary

subject

adjective uk us /ˈsʌbdʒɪkt/
subject to sth

often affected by something, especially something unpleasant:

Departure times are subject to alteration.

only able to happen if something else happens:

The pay rise is subject to approval by management.

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