| alcalino | alkaline |
| alcalino-terrosi | element of group II |
| alcaloide | alkaloid |
| Alcaloidi | Alkaloid |
| Alcalà de Xivert | Alcalà de Xivert |
| Alcalá | Alcalá |
| Alcalá de Guadaíra | Alcalá de Guadaíra |
| Alcalá de Henares | Alcalá de Henares |
| Alcamo | Alcamo |
| alcani | paraffin |
| alcanna | henna |
| alcano | alkane |
| Alcantara | Alcantara |
| Alcara Li Fusi | Alcara li Fusi |
| Alcatel | Alcatel |
| Alcatraz | Alcatraz Island |
| Alcazaba | Alcazaba |
| Alcañices | Alcañices |
| alce | moose |
| alce americano | moose |
| Alce Nero | Black Elk |
| Alcea rosea | Alcea rosea |
| Alcedo atthis | Common Kingfisher |
| Alcelafo | Buffalo |
| Alcelaphinae | Alcelaphinae |
| Alcelaphus buselaphus buselaphus | Bubal Hartebeest |
| Alceo | Alcaeus |
| Alces alces | Moose |
| Alceste | Alceste |
| Alcesti | Alcestis |
| alchechengi | bladder cherry |
| alchene | alkene |
| Alcheni | Alkene |
| Alchenstorf | Alchenstorf |
| Alchevsk | Alchevsk |
| Alchfrith di Deira | Alchfrith of Deira |
| Alchiba | Alpha Corvi |
| alchile | alkyl |
| alchimia | alchemy |
| alchimista | alchemist |
