ˈspīˌrȯid adjective
also spi·roi·dal (ˈ)spī|rȯid ə l
Etymology: spiroid from New Latin spiroïdes, from Greek speiroeidēs, from speira coil, twist + -oeidēs -oid; spiroidal International Scientific Vocabulary spiroid + -al — more at spire
: resembling a screw : spiral in form