metre vs rhythmicity

metre and rhythmicity both are nouns.

Word	Noun	Adjective	Verb	Adverb
metre	Yes	No	No	No
rhythmicity	Yes	No	No	No

As nouns, rhythmicity is a hypernym of metre; that is, rhythmicity is a word with a broader meaning than metre:

metre: rhythm as given by division into parts of equal duration
rhythmicity: the rhythmic property imparted by the accents and relative durations of notes in a piece of music

metre (noun)	rhythmicity (noun)
rhythm as given by division into parts of equal duration	the rhythmic property imparted by the accents and relative durations of notes in a piece of music
(prosody) the accent in a metrical foot of verse
the basic unit of length adopted under the Systeme International d'Unites (approximately 1.094 yards)