| altimeter | altímetro |
| Altingiaceae | Altingiaceae |
| Altino Arantes Building | Edificio del Banespa |
| Altiphrynoides | Altiphrynoides |
| Altiplano | Altiplano andino |
| Altirhinus | Altirhinus |
| Altispinax | Altispinax |
| altitude | elevación |
| altitude sickness | puna |
| Altkirch | Distrito de Altkirch |
| Altmark | Altmark |
| Altmarkkreis Salzwedel | Altmarkkreis Salzwedel |
| alto | contralto |
| Alto clarinet | Clarinete alto |
| Alto de El Angliru | Angliru |
| Alto Malcantone | Alto Malcantone |
| Alto Paraguay Department | Alto Paraguay |
| Alto Paraná Department | Departamento Alto Paraná |
| alto saxophone | saxofón alto |
| Alto Trás-os-Montes | Alto Trás-os-Montes |
| altocumulus | altocúmulo |
| Altocumulus Castellanu | Altocumulus castellanus |
| Altocumulus castellanus cloud | Altocumulus castellanus |
| Altocumulus cloud | Altocúmulus |
| Altocumulus undulatus cloud | Altocumulus undulatus |
| altogether | completamente |
| Altoparlante | Altavoz |
| Altorf | Altorf |
| Altos Hornos Zapla | Club Altos Hornos Zapla |
| altostratus | altostrato |
| Altostratus cloud | Altostratus |
| Altostratus undulatus cloud | Altostratus undulatus |
| Altrei | Anterivo |
| Altria Group | Altria Group |
| Altrice | Altricial |
| altrose | altrosa |
| altruism | altruismo |
| altruist | altruista |
| altruistic | altruista |
| Altstadt | Ciudad Vieja de Jerusalén |
| Altstätten | Altstätten |
| Altun Ha | Altún Ha |
| Altwiller | Altwiller |
| Altyn-Tagh | Falla de Altyn Tagh |
| Altzaga | Alzaga |
| Altötting | Distrito de Altötting |
| ALU | Unidad aritmético lógica |
| Alu Alkhanov | Alu Alkhanov |
| Alu sequence | Secuencia Alu |
| Alucard | Alucard |
| alum | alumbre |
| alumina | alúmina |
| aluminium | aluminio |
| aluminium container | envase de aluminio |
| aluminium content | contenido de aluminio |
| aluminium foil | papel aluminio |
| Aluminium gallium arsenide | Arseniuro de galio-aluminio |
| aluminium industry | industria del aluminio |
| Aluminium oxide | Alúmina |
| aluminosilicate | aluminosilicato |
| Aluminothermic reaction | Isoptera |
| aluminum | aluminio |
| Aluminum coating | Aluminizado |
| aluminum foil | papel de aluminio |
| Alumium coating | Aluminizado |
| alumna | ex-alumna |
| alumnus | ex-alumno |
| Alundum | Corindón |
| alunite | alunita |
| Alutiiq | Idioma alutiiq |
| Alutiiq language | Idioma alutiiq |
| Alva Myrdal | Alva Myrdal |
| Alvan Graham Clark | Alvan Graham Clark |
| Alvaneu | Alvaneu |
| Alvar Aalto | Alvar Aalto |
| Alvar Aalto Medal | Premio Alvar Aalto |
| Alvarezsaurus | Alvarezsaurus |
| Alvaro Ormeño | Álvaro Ormeño |
| Alvaschein | Alvaschein |
| alveolar | alveolar |
| Alveolar consonant | Consonante alveolar |
| Alveolar nasal | Nasal alveolar |
| alveolus | alveolo |
| Alves dos Reis | Artur Virgílio Alves dos Reis |
| Alvesta Municipality | Alvesta |
| Alvin and the Chipmunks | Nickelodeon |
| Alvin Toffler | Alvin Toffler |
| Alvin York | Sargento York |
| Alvina | Alwine |
| Alvis Cars | Alvíss |
| Alvíss | Alvíss |
| Alvíssmál | Alvíssmál |
| Alwalkeria | Alwalkeria |
| Alwar | Álvaro |
| always | continuamente |
| Alxasaurus | Alxasaurus |
| Alyattes II | Aliates |
| Alyki | Aliki |
| Alyson Hannigan | Alyson Hannigan |
| Alyssa Milano | Alyssa Milano |
| Alytus | Condado de Alytus |
| Alytus County | Condado de Alytus |
| Alytus district municipality | Condado de Alytus |
| Alyx Vance | Alyx Vance |
| Alzatea | Alzateaceae |
| Alzey | Alzey |
| Alzey-Worms | Distrito de Alzey-Worms |
| Alzheimer disease | Enfermedad de Alzheimer |
| Alzheimer's disease | Enfermedad de Alzheimer |
| Alzira | Alcira |
| Alzon | Alzonne |
| Alçay-Alçabéhéty-Sunharette | Alçay-Alçabéhéty-Sunharette |
| Alès | Alès |
| Alénya | Alénya |
| Aléria | Aléria |
| Alí Primera | Alí Primera |
| Alí Rodríguez Araque | Alí Rodríguez Araque |
| Alû | Alû |
| AM | maestro en humanidades |
| AM Canum Venaticorum star | Estrellas AM Canum Venaticoru |
| AM Herculis star | Estrellas AM Herculis |
| AM star | Estrella AM |
| Am Timan | Am Timan |
| Ama-no-Uzume | Ama no Uzume |
| Amacayacu National Park | Parque Amacayacu |
| Amadeo Bordiga | Amadeo Bordiga |
| Amadeo I of Spain | Amadeo I de España |
| Amadeus | Amadeus |
| Amadeus CRS | Amadeus |
| Amadeus II of Savoy | Amadeo II de Saboya |
| Amadeus III of Savoy | Amadeo III de Saboya |
| Amadeus IV of Savoy | Amadeo IV de Saboya |
| Amadis de Gaula | Amadís de Gaula |
| Amado Garcia Guerrero | Amado García Guerrero |
| Amadocus I | Amádoco I |
| Amadora | Amadora |
| Amadou Bamba | Amadou Bamba |
| Amadou Toumani Touré | Amadou Toumani Touré |
| Amal Movement | Movimiento Amal |
| Amalafrida | Amalafrida |
| Amalaric | Amalarico |
| Amalasuntha | Amalasunta |
| Amalfi | Amalfi |
| Amalfi Coast | Costa Amalfitana |
| amalgam | amalgama |
| amalgamate | amalgamar |
