sitting vs session

sitting and session both are nouns.

Word	Noun	Adjective	Verb	Adverb
sitting	Yes	Yes	No	No
session	Yes	No	No	No

As nouns, session is a hypernym of sitting; that is, session is a word with a broader meaning than sitting:

As nouns, sitting and session are synonyms defined as:

Other synonyms of sitting include seance.

sitting (noun)	session (noun)
the act of assuming or maintaining a seated position	a meeting devoted to a particular activity
(photography) the act of assuming a certain position (as for a photograph or portrait)	a meeting for execution of a group's functions
a session as of a legislature or court	a meeting of spiritualists
a meeting of spiritualists	the time during which a school holds classes

sitting (adjective)	session (adjective)
(of persons) having the torso erect and legs bent with the body supported on the buttocks
not moving and therefore easy to attack