| arcates | ark |
| arcaísmo | archaism |
| Arce | Arce - Artzi |
| Arceau | Arch |
| Arcebispado de Mainz | Archbishopric of Mainz |
| Arcebispado de Riga | Archbishopric of Riga |
| arcebispo | archbishop |
| Arcebispo da Cantuária | Archbishop of Canterbury |
| Arcebispo Damaskinós | Archbishop Damaskinos |
| Arcebispo de Armagh | Archbishop of Armagh |
| Arcebispo do Monte Sinai e Raithu | Archbishop of Mount Sinai and Raithu |
| arcediago | archdeacon |
| Arcelor Mittal | Arcelor Mittal |
| Arceàpado de Mayence | Bishop of Mayence |
| Arch Linux | Arch Linux |
| Archaea | Archaea |
| Archaeobatrachia | Archaeobatrachia |
| Archaeocyatha | Archaeocyatha |
| Archaeplastida | Archaeplastida |
| Archeiro | Archer |
| Archer John Porter Martin | Archer John Porter Martin |
| Archiannelida | Haplodrili |
| Archibald Vivian Hill | Archibald Hill |
| Archidamos III | Archidamus III |
| Archidamus III | Archidamus III |
| Archie Hahn | Archie Hahn |
| Archostemata | Archostemata |
| Archote | Handheld sungun |
| archotes | hoop |
| Arché | Arche |
| Arcins | Arsenic |
| Arcjet rocket | Arcjet rocket |
| Arcnet | ARCNET |
| arco | bow |
| arco composto | compound bow |
| Arco de Constantino | Arch of Constantine |
| Arco de Septímio Severo | Arch of Septimius Severus |
| Arco de Tito | Arch of Titus |
| Arco do triunfo | Triumphal arch |
| arco e flecha | bow and arrow |
| arco e flecha (esporte) | live |
| Arco faríngeo | Branchial arch |
| Arco Geodésico de Struve | Struve Geodetic Arc |
| Arco insular | Island arc |
| arco longo | longbow |
| Arco palmar profundo | Deep palmar arch |
| Arco senil | Arcus senilis |
| arco triunfal | triumphal arch |
| Arco vulcânico | Island arc |
| arco-e-flecha | archery |
| arco-inimigo | arch-enemy |
| arco-soldagem | arc welding |
| arco-íris | rainbow |
| arcobotante | buttress |
