Meaning of “clash” - Learner’s Dictionary

clash

verb uk us /klæʃ/
FIGHT [ I ]

to fight or argue:

Government troops clashed with rebel soldiers.
Many young people clash with their parents over what time they must be home at night.
COLOUR [ I ]

If colours or styles clash, they do not look good together:

You can't wear pink lipstick - it clashes with your dress.
EVENT [ I ] UK

If two events clash, they happen at the same time so that you cannot go to them both:

Emma's party clashes with my brother's wedding.
NOISE [ I, T ]

to make a loud noise by hitting metal objects together

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