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