undercut
v.v. to sell something at a lower price than your competitors. You can also use it to describe making someone's position or argument weaker.
v. to offer goods or services at a lower price than a competitor; by extension, to weaken or destabilise a person, position, or argument. Transitive — requires a direct object.
The new supermarket tries to undercut the local shops.
By lowering their subscription fees, the startup managed to undercut the established market leaders and gain thousands of users.
The witness's sudden admission of a prior friendship with the defendant served to undercut the prosecution's entire theory of a random, unprovoked attack.
From Middle English undercutten, equivalent to under- + cut.
The verb is transitive and takes a direct object.
They undercutted the price.They undercut the price.The past tense and past participle of 'undercut' is 'undercut', not 'undercutted'.