Answer: ele

AnswerCrossword Clue
ELEPrefix with commute
ELELetter after ka in Spanish
ELEIt follows ka in the Spanish alphabet
ELEAisle: Obs.
ELEEel: Old spelling.
ELEConger, old style
ELEMoray, old style
ELESpanish "L"
ELEThreat to humanity, in "Deep Impact"