leaven agent vs leavening agent

leaven agent and leavening agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
leaven agent	Yes	No	No	No
leavening agent	Yes	No	No	No

As nouns, leaven agent and leavening agent are synonyms defined as:

leaven agent and leavening agent: A leavening agent (also known as raising agent or leaven agent) is a substance added to dough or batter to make it lighter and softer.

Other synonyms of leaven agent include raising agent.

leaven agent (noun)	leavening agent (noun)
A leavening agent (also known as raising agent or leaven agent) is a substance added to dough or batter to make it lighter and softer.	A leavening agent (also known as raising agent or leaven agent) is a substance added to dough or batter to make it lighter and softer.