open-chain

from WordNet (r) 3.0 (2006)

open-chain
    adj 1: having an open chain structure [syn: {acyclic}, {open-
           chain}] [ant: {cyclic}]

from The Collaborative International Dictionary of English v.0.48

open-chain \open-chain\ adj. (Chemistry)
   not cyclic; having no rings of atoms within the molecular
   structure; having an open chain structure. Opposite of