sketch vs adumbrate

sketch is a noun but adumbrate is not a noun.

Word	Noun	Adjective	Verb	Adverb
sketch	Yes	No	Yes	No
adumbrate	No	No	Yes	No

As verbs, sketch and adumbrate are synonyms defined as:

sketch and adumbrate: describe roughly or briefly or give the main points or summary of

Other synonyms of sketch include outline.

sketch (noun)	adumbrate (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

sketch (verb)	adumbrate (verb)
describe roughly or briefly or give the main points or summary of	describe roughly or briefly or give the main points or summary of
make a sketch of	give to understand