The suffix "-oid" means the same as "quasi", so "resembling", "like". A *groupoid* is a quasi-group, like a group. There are <A HREF="https://www.thefreedictionary.com/words-that-end-in-oid">hundreds of words</A> in that category, covering many scientific disciplines. In the "early use of mathematical words" <a href="https://jeff560.tripod.com/c.html">database</a> I find: 250 BC: conchoid 200 BC: cissoid 400: trapezoid 1650: trochoid 1672: ellipsoid 1685: cochleoid 1830: epicycloid 1836: paraboloid 1837: strophoid 1844: centroid 1872: geoid, gyroid 1878: nephroid 1879: deltoid 1881: prismatoid 1891: cuboid 1925: groupoid 1935: matroid <A HREF="https://www.nytimes.com/1984/02/05/magazine/on-language-the-woid-on-oid.html">The Woid on-Oid</A> by William Safire comments on the proliferation of -oids: > We all know that the use of -oid to create a noun has been growing by > leapoids and bounds. Among the earliest were android, or "automaton > in human form," created in 1727, and asteroid, "small body like a > star," in 1802. Scientists and mathematicians were especially > attracted to the ending, juggling their cylindroids, globoids and > spheroids.