| Word | Definitions | Synonyms |
|---|---|---|
| apteryx | (noun) nocturnal flightless bird of New Zealand having a long neck and stout legs; only surviving representative of the order Apterygiformes | Synonyms: kiwi |
| aptitude | (noun) inherent ability | - |
| aptness | (noun) appropriateness for the occasion | Synonyms: appositeness |
| (noun) a disposition to behave in a certain way | Synonyms: propensity |