In a dear or precious manner. / In a dear or expensive manner. / At great expense.

(figuratively) To suffer as a result of one's actions.

simple past tense and past participle of sell dearly

(idiomatic, especially military, of a fighting person, unit, or vehicle) To make one's opponent pay a very high price to defeat or obtain (a person, unit, vehicle, or territory).

Third-person singular simple present indicative form of sell dearly

present participle of sell dearly

To do great injury to the enemy before being killed by them.