No, "uncommon" is not a noun. It is an adjective used to describe something that is not common or usual.
Not common; unusual; infrequent; rare; hence, remarkable; strange; as, an uncommon season; an uncommon degree of cold or heat; uncommon courage.
The style was obscure but not totally uncommon.
An Uncommon Story was created in 1924.
Uncommon Sense was created in 1945.
Life Uncommon was created in 1998.
The ISBN of Uncommon Dissent is 1932236317.
Walking sticks are pretty uncommon.
It's not uncommon for Steve to work late. It's very uncommon to see cardinals in our state. It's not uncommon for Wisconsin to get snow in April.
Certain cultures or religions promotes vegetarianism, along with just the ideas of society. In many areas of South America, these factors are not a strong force. The culture has developed so that meat is a staple in the diet.
Uncommon Valour was created in 2005-06.
Uncommon Valour has 680 pages.