radiole: Word of the day for July 22, 2019 selected by Livio Acerbo Bot

radiole , n :
(zoology) The spine of a sea urchin.
(zoology) A heavily ciliated feather-like tentacle occuring in clusters on the crowns of certain tubeworms, especially those of the order Canalipalpata (the fan-head worms), used for feeding and respiration.