| Arctic Ocean | Océano Glacial Ártico |
| Arctic warfare | Guerra ártica |
| Arctic Wolf | Canis lupus arctos |
| Arctic Zone | Ártico |
| Arctic-alpine botanic garden | Jardín Botánico Ártico-Alpino de Tromsø |
| Arctiidae | Arctiidae |
| Arctinus of Miletus | Arctino de Mileto |
| Arctodus | Arctodus |
| Arctostaphylos | Arctostaphylos |
| Arctostaphylos alpina | Arctostaphylos alpina |
| Arctostaphylos uva-ursi | Arctostaphylos uva-ursi |
| Arctotheca calendula | Arctotheca |
| Arctotis | Arctotis |
| Arcturus | Arturo |
| Arcueil | Arcueil |
| Arcus Argentariorum | Arco de Severo Séptimo |
| Ard-galen | Ard-Galen |
| Ardabil | Ardebil |
| Ardabil Province | Provincia de Ardabil |
| Ardabīl Province | Provincia de Ardabil |
| Ardahan Province | Provincia de Ardahan |
| Ardaric | Ardarico |
| Ardashir I | Ardacher I |
| Ardashir II | Ardacher II |
| Ardea | Ardeidae |
| Ardea alba | Ardea alba |
| Ardeatine massacre | Masacre de las Fosas Ardeatinas |
| Ardennes | Ardenas |
| ardent | ansioso |
| ardently | fogoso |
| Ardeola | Ardeola |
| Ardez | Ardez |
| Ardhanari | Ardhanari |
| Ardillières | Ardillières |
| Ardipithecus | Ardipithecus |
| Ardipithecus ramidus | Ardipithecus ramidus |
| Ardo | Ardón |
| Ardon | Ardon |
| ardor | ardor |
| ardour | exaltacion |
| Ardulfurataini Watan | Ardulfurataini Watan |
| arduous | duro |
| arduously | trabajoso |
| arduousness | rigor |
| arduousnesses | dificultades |
| Ardys II | Ardis de Lidia |
| Ardèche | Ardèche |
| Ardèche River | Río Ardèche |
| are | cien metros cuadrados |
| area | recinto |
| area code | prefijo telefónico |
| Area de Conservación Guanacaste World Heritage Site | Área de Conservación de Guanacaste |
| area of potential pollution | área de contaminación potencial |
