signal vs bespeak

signal is a noun but bespeak is not a noun.

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

As verbs, signal and bespeak are synonyms defined as:

Other synonyms of signal include betoken, indicate, point.

signal (noun)	bespeak (noun)
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

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

signal (verb)	bespeak (verb)
communicate silently and non-verbally by signals or signs	express the need or desire for
be a signal for or a symptom of	be a signal for or a symptom of