Conchoid
/ˈkɒŋ.kɔɪd/noun
A curve defined by a fixed point and a fixed line, used in geometry.
Did you know?Conchoid comes from Greek konkhē, “shell,” plus -oid, “resembling,” so the word literally means a shell-shaped form—proof that geometry borrowed its language from nature.
Etymological Timeline
Ancient Greek
Greek
konkhē (κόγχη)
“shell; shellfish; also a hollow or cavity”
Classical Greek
Greek
konchoeidēs (κογχοειδής)
“shell-shaped, resembling a shell”
Late Latin
Latin
conchoides
“shell-like; a geometric term for a curve resembling a shell”
16th Century
French
conchoïde
“a shell-shaped curve in mathematics”
17th Century
English
conchoid
“a geometric curve derived from a fixed point and line”