Alternative forms 
The word scimitar, known in English since 1548, derived from Medieval French cimeterre (15c.) or directly from Italian scimitarra, of unknown origin. Ottoman Turkish would be the expected source, but no such word has been found there.
A possible origin of scimitar is from the Persian shim- or shamshir. This, in turn, is said to be derived from Middle Persian shafshēr meaning; lion's claw (sham = claw, shir = lion), in reference to the sword's curve. However, this is likely a folk etymology, as the word is already attested in Middle persian with the meaning sword.
scimitar (plural scimitars)