| Aruncus | Aruncus |
| Arundinaria | Arundinaria |
| Arundo | Arundo |
| Arundo donax | Arundo donax |
| Arusha | Arusha |
| Arvanita | Arvanites |
| arveja | pea |
| Arvejas | Garbanzo beans |
| arvejas secas | split pea |
| Arverno | Arverni |
| Arvicola sapidus | Southwestern Water Vole |
| Arvid | ArVid |
| Arvid Carlsson | Arvid Carlsson |
| Arvigo | Arvigo |
| Arvo Pärt | Arvo Pärt |
| Arwen | Arwen |
| ArXiv | ArXiv |
| Arya | Arya Dröttningu |
| Aryabhata | Aryabhata |
| Arzal | Arzal |
| Arzawa | Arzawa |
| Arzier | Arzier |
| Arzobispado de Colonia | Archbishopric of Cologne |
| Arzobispado de Salzburgo | Archbishopric of Salzburg |
| Arzobispado de Sevilla | Roman Catholic Archdiocese of Seville |
| Arzobispado de Tanger | Roman Catholic Archdiocese of Tanger |
| arzobispal | archiepiscopal |
| arzobispo | archbishop |
| Arzobispo de Armagh | Archbishop of Armagh |
| Arzobispo de Canterbury | Archbishop of Canterbury |
| Arzobispo de México | Roman Catholic Archdiocese of Mexico |
| Arzobispo de Toledo | Roman Catholic Archdiocese of Toledo |
| Arzon | Arzon |
| arábico | Arabic |
| arácnido | arachnid |
| arácnidos | arachnids |
| Arájova | Arachova |
| Arán | Haran |
| arándano | bilberry |
| arándano agrio | cranberry |
| arándano rojo | cranberry |
| Aránzazu | Arantzazu |
| Arévacos | Arevaci |
| Aríbalo | Aryballos |
| Arístides | Aristides |
| Arístides Maillol | Aristide Maillol |
| Arístipo | Aristippus |
| as | whizz |
| as de corazones | ace of hearts |
| as de diamantes | ace of diamonds |
| as de guía | bowline |
| as de oros | ace of diamonds |
| as de tréboles | ace of clubs |
| as en la manga | ace in the hole |
| As Salam al Amiri | As Salam al Amiri |
| As Sulaymaniyah | As Sulaymaniyah Governorate |
