Meaning of -A in English

-A

~ 1

■ suffix forming:

1》 ancient or Latinized modern names of animals and plants: primula.

2》 names of oxides: baryta.

3》 geographical names: Africa.

4》 ancient or Latinized modern feminine forenames: Lydia.

5》 nouns from Italian, Portuguese, and Spanish: stanza.

Origin

representing a Gk, L., or Romance feminine singular

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~ 2

■ suffix forming plural nouns:

1》 from Greek or Latin neuter plurals corresponding to a singular in -um or -on (such as addenda , phenomena ).

2》 in names (often from modern Latin) of zoological groups: Insectivora.

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~ 3

■ suffix informal

1》 of: coupla.

2》 have: mighta.

3》 to: oughta.

Concise Oxford English vocab.      Сжатый оксфордский словарь английского языка.