regular vs regularity

regular and regularity both are nouns.

Word	Noun	Adjective	Verb	Adverb
regular	Yes	Yes	No	No
regularity	Yes	No	No	No

regular (noun)	regularity (noun)
a garment size for persons of average height and weight	the quality of being characterized by a fixed principle or rate
a regular patron	a property of polygons: the property of having equal sides and equal angles
a dependable follower (especially in party politics)
a soldier in the regular army

regular (adjective)	regularity (adjective)
in accordance with fixed order or procedure or principle
(of solids) having clear dimensions that can be measured; volume can be determined with a suitable geometric formula
(used of the military) belonging to or engaged in by legitimate army forces
not constipated
relating to a person who does something regularly
officially full-time
not deviating from what is normal
regularly scheduled for fixed times
conforming to a standard or pattern
occurring at fixed intervals
symmetrically arranged
often used as intensifiers
in accord with regular practice or procedure