The suffix "-oid" means the same as "quasi", so "resembling", "like". A groupoid is a quasi-group, like a group.
From the "early use" database I find:
250 BC: conchoid
200 BC: cissoid
1685: cochleoid
1830: epicycloid
1844: centroid
1872: geoid, gyroid
1881: prismatoid
1891: cuboid
