defect

noun1 of 2

a problem; a fault

• “The product is guaranteed to be free from defects.”Tatoeba
• “There must be a defect in the experimental method.”Tatoeba

Sentences from Tatoeba show real usage. A word can have several meanings, so a sentence may use another one.

verb2 of 2

To abandon or turn against; to cease or change one's loyalty, especially from a military organisation or political party.