Meaning

• A fault or malfunction.

  "a defect in the ear or eye; a defect in timber or iron; a defect of memory or judgment"

• The quantity or amount by which anything falls short.

• A part by which a figure or quantity is wanting or deficient.

Meaning

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

• To desert one's army, to flee from combat.

• To join the enemy army.

• To flee one's country and seek asylum.