similar

Two things called similar were originally imagined as belonging together—as one group, one pattern, one recognizable kind. Latin similis meant “like” or “resembling,” and it was connected with simul, “together,” which also survives in words such as ensemble and simultaneously. English borrowed the adjective through French similaire and Medieval Latin similaris; it first appears in English in the 1610s, just as scientific classification was becoming increasingly important. The same Latin family took a darker turn in dissimulate and dissemble: to “make like” could mean creating a convincing false appearance, hiding what was really there. So when two triangles are similar, they are not twins—they are the same geometrical idea wearing different sizes, positions, or rotations.