A physical or moral defect, imperfection; unsoundness; “anything bad.”​—De 17:1.

The Hebrew word for a physical or moral “defect” is mum. (Le 21:17; Job 31:7) The Greek moʹmos means “blemish,” while the related aʹmo·mos means “without blemish.” (2Pe 2:13; Eph 1:4) Both are related to the root mo·maʹo·mai, meaning “find fault with.”​—2Co 6:3; 8:20.

In contrast with Jehovah, who is ‘perfect in his activity [“without blemish (spotless) are his works,” Sy],’ of Israel God said: “They have acted ruinously on their own part; they are not his children, the defect is their own.”​—De 32:4, 5.

A Levitical priest ministering before the God of perfection, therefore, had to be free from such physical blemishes as blindness, lameness, a slit nose, abnormalities such as an elongated hand, a hunched back, fractured hand, consumptive thinness, eye or skin diseases, a broken hand or foot, and broken or crushed testicles. (Le 21:18-20) Free from such defects, Israel’s high priest well represented the Great High Priest Jesus Christ, who is “guileless, undefiled.”​—Heb 7:26.

Soundness, freedom from blemish, was required of the sacrificial animals under the Mosaic Law. (Ex 12:5; Le 4:3, 28; De 15:21) The same was also true of the sacrifices in connection with the pictorial temple envisioned by Ezekiel. (Eze 43:22, 23) In like manner, Christ, “an unblemished and spotless lamb,” “offered himself without blemish to God.”​—1Pe 1:19; Heb 9:14.

Among persons whose physical appearance is described as having “no defect” were Absalom, the Shulammite girl, and certain sons of Israel in Babylon. (2Sa 14:25; Ca 4:7; Da 1:4) Everyone under the Law was encouraged to watch out for and protect one another, lest they become blemished in any way. “In case a man should cause a defect in his associate, then just as he has done, so it should be done to him. Fracture for fracture, eye  for eye, tooth for tooth; the same sort of defect he may cause in the man, that is what should be caused in him.” (Le 24:19, 20) The apostle expressed concern over keeping the Christian congregation free from blemishes in a spiritual sense.​—Eph 1:4; 5:27; Col 1:22; see also Jude 24.