1. (adj)closed chain, ring (chemistry) a chain of atoms in a molecule that forms a closed loop Synonyms: doughnut, band, mob, hoop, annulus, tintinnabulation, ring, gang, anchor ring, pack, halo, ringing, closed chain Antonyms: open chain, open-chain, acyclic
2. (adj)closed-chain, closed-ring having atoms linked by bonds represented in circular or triangular form Synonyms: closed-chain, closed-ring Antonyms: open chain, acyclic, open-chain