defect

(noun) an imperfection in a bodily system. Examples: "Visual defects." "This device permits detection of defects in the lungs."

(noun) a failing or deficiency. Synonyms: shortcoming. Example: "That interpretation is an unfortunate defect of our lack of information."

(noun) an imperfection in an object or machine. Synonyms: fault, flaw. Examples: "A flaw caused the crystal to shatter." "If there are any defects you should send it back to the manufacturer."

(noun) a mark or flaw that spoils the appearance of something (especially on a person's body). Synonyms: blemish, mar. Example: "A facial blemish."

(verb) desert (a cause, a country or an army), often in order to join the opposing cause, country, or army. Synonyms: desert. Example: "If soldiers deserted hitler's army, they were shot."