Overrun and Whelm

Overrun verb - To enter for conquest or plunder.

Whelm and overrun are semantically related In some cases you can use "Whelm" instead a verb "Overrun".

Whelm verb - To subject to incapacitating emotional or mental stress.

Overrun and whelm are semantically related in flood topic. Sometimes you can use "Overrun" instead a verb "Whelm", if it concerns topics such as absorb, drown, inundate with water.