jag (1)EnglishOxford Dictionary of Englishjag1 /dʒaɡ / ▸ noun a sharp projection. ▪ mainly Scottish English an injection. ▸ verb ( jags, jagging, jagged) [with object] stab, pierce, or prick: she jagged herself in the mouth. – DERIVATIVES jagger /ˈdʒaɡə / noun– ORIGIN late Middle English (in the sense ‘stab, pierce’): perhaps symbolic of sudden movement or unevenness (compare with jam1 and rag1).