grand theft vs thieving

grand theft and thieving both are nouns.

Word	Noun	Adjective	Verb	Adverb
grand theft	Yes	No	No	No
thieving	Yes	Yes	No	No

As nouns, thieving is a hypernym of grand theft; that is, thieving is a word with a broader meaning than grand theft:

grand theft: larceny of property having a value greater than some amount (the amount varies by locale)
thieving: the act of taking something from someone unlawfully

Other hypernyms of grand theft include larceny, stealing, theft, thievery.

grand theft (noun)	thieving (noun)
larceny of property having a value greater than some amount (the amount varies by locale)	the act of taking something from someone unlawfully

grand theft (adjective)	thieving (adjective)
	given to thievery