jag (1)EnglishOxford New American Dictionaryjag1 /jaɡ, dʒæɡ / ▸ noun a sharp projection. ▸ verb (jags, jagging, jagged /ˈjaɡd/) [with object] stab, pierce, or prick: she jagged herself in the mouth. – DERIVATIVES jagger /ˈjaɡər, ˈdʒæɡər / noun– ORIGIN late Middle English (in the sense ‘stab, pierce’): perhaps symbolic of sudden movement or unevenness (compare with jam1 and rag1).