chalk out vs sketch

chalk out is not a noun while sketch is a noun.

Word	Noun	Adjective	Verb	Adverb
chalk out	No	No	Yes	No
sketch	Yes	No	Yes	No

As verbs, chalk out and sketch are synonyms defined as:

chalk out (noun)	sketch (noun)
	preliminary drawing for later elaboration
	short descriptive summary (of events)
	a humorous or satirical drawing published in a newspaper or magazine
	a brief literary description

chalk out (verb)	sketch (verb)
make a sketch of	describe roughly or briefly or give the main points or summary of
	make a sketch of