signaller vs signal

signaller and signal both are nouns.

Word	Noun	Adjective	Verb	Adverb
signaller	Yes	No	No	No
signal	Yes	Yes	Yes	No

signaller (noun)	signal (noun)
someone who communicates by signals	any nonverbal action or gesture that encodes a message
	any incitement to action
	an electric quantity (voltage or current or field strength) whose modulation represents coded information about the source from which it comes

signaller (adjective)	signal (adjective)
	notably out of the ordinary

signaller (verb)	signal (verb)
	communicate silently and non-verbally by signals or signs
	be a signal for or a symptom of