헤엄치다 (heeomchida) means “swim”

More examples

어제 바다에서 친구들과 헤엄쳤어요.eo je pa da e seo chin gu deul gwa he eom cheo sseo yo

Yesterday, I swam in the sea with my friends.

A body moves forward through water with repeated strokes, either at the surface or below it.

수영하다suyeonghada: Swim in water as a sport or leisure activity.
헤엄쳐 가다heeomcheo kada: Go in a direction while swimming.

물 위나 물속에서 몸을 저어 움직여 나아가는 동작을 이르는 동사.mul wi na mul so ge seo mo meul cheo eo um ji gyeo na a ga neun tong ja geul i reu neun tong sa

The verb combines 헤엄 (heeom, "swimming") with 치다 (chida, "to hit"), using 치다 in an extended sense for repeated movement through water.

In conversation, it commonly appears in patterns showing an action in progress or movement toward a place, so it helps describe what someone is doing now.