Definition of pentacyclic in English:

pentacyclic

adjective

  • 1Botany (of a flower) having the parts arranged in five whorls (rare).

  • 2Chemistry having five rings of atoms in the molecule.

Origin

Late 19th century; earliest use found in Alfred Bennett (1833–1902), botanist and publisher. From penta- + ancient Greek κύκλος cycle + -ic, after German pentacyclisch.