hyponym

The specific term used to designate a member of a class.

X is a hyponym of Y if X is a (kind of) Y.

 

		hyponym
tree		oak	an oak is a kind of tree
plant		tree	a tree  is a kind of plant
dwelling		house	a house is a kind of dwelling
disatisfaction		disappointment	disappointment is a kind of disatisfaction

see hypernym (the inverse relation)