To reduce or curtail drastically:
To provide (a gun, electric battery, etc.) with too little or too low a charge
To write down.
To be approved of; gain acceptance:
Find another word for undersell. In this page you can discover 10 synonyms, antonyms, idiomatic expressions, and related words for undersell, like: undercut, reduce, slash, cut, undercharge, mark down, sell, oversell, embarrass and short-change.