| Argumentum ad baculum | Argumentum ad baculum |
| Argumentum ad hominem | Ad hominem |
| Argumentum ad ignorantiam | Argument from ignorance |
| Argusianus | Argusianus |
| Argusianus argus | Great Argus |
| arguto | scintillating |
| arguzia | facetiousness |
| Argy | Argis |
| Argyll | Argyll |
| Argyll e Bute | Argyll and Bute |
| Argyrosaurus superbus | Argyrosaurus |
| argènteo | silver |
| Arhansus | Arhansus |
| Ari Þorgilsson | Ari Þorgilsson |
| aria | aspect |
| aria condizionata | air-conditioning |
| aria fredda | cold air |
| Aria Giovanni | Aria Giovanni |
| aria respiratoria | respiratory air |
| Aria ricircolata | Circulating air |
| aria viziata | fug |
| aria-aria | air-to-air |
| aria-terra | air-to-surface |
| Ariadne | Ariadne |
| Ariadne Oliver | Ariadne Oliver |
| ariana | Aryan |
| Arianesimo | Arianism |
| Arianespace SA | Arianespace |
| Arianna | Ariadne |
| Arianna Fontana | Arianna Fontana |
| ariano | Aryan |
| Ariano Irpino | Ariano Irpino |
| Ariary malgascio | Malagasy ariary |
| Ariballo | Aryballos |
| Aribe | Aribe |
| aridità | aridity |
| arido | waste |
| aridocoltura | dry farming |
