non-cyclic
/nɒnˈsʌɪklɪk/ /nɒnˈsɪklɪk/adjective
1That does not form part of a cycle; not involving or relating to cycles.
2 Chemistry. Having or designating a molecular structure containing no closed rings of atoms.
Origin
Late 19th century; earliest use found in Philosophical Transactions of the Royal Society of London. From non- + cyclic.