Definition of planispiral in English:

planispiral

adjective

  • Forming a flat coil; of or relating to a flat spiral form, as the shell of certain molluscs (including many fossil species), the proboscis of a butterfly or moth, etc.

Origin

Late 19th century; earliest use found in The Century Dictionary. From plani- + spiral [adverb].

Pronunciation

planispiral

/ˌpleɪnɪˈspʌɪr(ə)l//ˌpleɪnɪˈspʌɪrəl/