Heliotaxis
/ˌhiːli.oʊˈtæk.sɪs/noun
The movement or orientation of an organism in response to sunlight.
Did you know?The second half comes from Greek *taxis*, a word tied to arranging troops in battle, so this scientific term literally frames sunlight-response as a kind of ordered march.
Etymological Timeline
Ancient Greek
Greek
hḗlios
“sun”
Ancient Greek
Greek
táxis
“arrangement, order, military formation”
Late 19th Century
English
heliotaxis
“a movement or orientation in response to sunlight”
Modern English
English
heliotaxis
“movement or orientation toward or away from the sun”