sell vs sell up

sell is a noun but sell up is not a noun.

Word	Noun	Adjective	Verb	Adverb
sell	Yes	No	Yes	No
sell up	No	No	Yes	No

sell (noun)	sell up (noun)
the activity of persuading someone to buy

sell (verb)	sell up (verb)
persuade somebody to accept something	sell or get rid of all one's merchandise
exchange or deliver for money or its equivalent
do business; offer for sale as for one's livelihood
give up for a price or reward
deliver to an enemy by treachery
be sold at a certain price or in a certain way
be responsible for the sale of
be approved of or gain acceptance