buoyancy vs irrepressibility

buoyancy and irrepressibility both are nouns.

Word	Noun	Adjective	Verb	Adverb
buoyancy	Yes	No	No	No
irrepressibility	Yes	No	No	No

As nouns, buoyancy and irrepressibility are synonyms defined as:

buoyancy (noun)	irrepressibility (noun)
the property of something weightless and insubstantial	irrepressible liveliness and good spirit
irrepressible liveliness and good spirit
the tendency to float in water or other liquid
cheerfulness that bubbles to the surface