un‧der‧sell /ˌʌndəˈsel $ -ər-/ verb (past tense and past participle undersold /-ˈsəʊld $ -ˈsoʊld/) [transitive]

1. to sell goods at a lower price than someone else

2. to make other people think that someone or something is less good, effective, skilful etc than they really are:
I think he undersold himself at the interview.

[TahlilGaran] Dictionary of Contemporary English ▲