Greek alphabet vs lambda

Greek alphabet and lambda both are nouns.

Word	Noun	Adjective	Verb	Adverb
Greek alphabet	Yes	No	No	No
lambda	Yes	No	No	No

Greek alphabet (noun)	lambda (noun)
the alphabet used by ancient Greeks	the craniometric point at the junction of the sagittal and lamboid sutures of the skull
	the 11th letter of the Greek alphabet