조심해요 · 조심했어요 · 조심할 거예요 · 조심하세요
to be careful, to watch out
Example
눈이 와서 길이 미끄러우니까 운전 조심하세요.
It snowed and the roads are slippery, so drive carefully.
Word parts
조 hold+심 heart, mind
Literally 'hold the heart': keep your mind in check.
Good to know
조심히 가세요 ('Get home safely') is a common, caring way to say goodbye.