| Bachir Gemayel | Bashir Gemayel |
| bacilli | bacterias |
| bacillus | bacilo |
| Bacillus anthracis | Bacillus anthracis |
| Bacillus Calmette-Guérin | Bacillus Calmette-Guerin |
| back | defensa |
| back away | alejarse |
| back cover | contraportada |
| back door | puerta trasera |
| back down | echarse atrás |
| Back draught | Acojinamiento |
| back fire | contrafuego |
| Back for the First Time | Back For The First Time |
| Back in Black | Back In Black |
| back of beyond | quinto pino |
| back of the head | nuca |
| back off | echarse atrás |
| back out | echarse atrás |
| back pedaling | marcha atrás |
| back pedalling | marcha atrás |
| Back rank checkmate | Mate del pasillo |
| back road | camino vecinal |
| back seat | asiento trasero |
| Back streets | Barrios bajos |
| back support | respaldo |
| back talk | impertinencia |
| Back to Basics | Back to Basics |
| Back to Basics Tour | Back To Basics World Tour |
| Back to Bedlam | Back to Bedlam |
| Back to Black | Back to Black |
| back to front | al revés |
| Back To Jerusalem movement | Retorno a Jerusalén |
| Back to the Egg | Back to the Egg |
| Back to the Future | Regreso al futuro |
| Back to the Future Part II | Back to the future II |
| Back to the Future Part III | Back To The Future III |
| Back to the Future trilogy | Regreso al futuro |
| back up | embotellamiento |
| back vowel | vocal posterior |
| back window | ventanilla trasera |
| back yard | traspatio |
| back-formation | formación regresiva |
| back-to-back | espaldera |
| back-up | apoyo |
| back-up file | fichero de reserva |
| back-up light | luz de retroceso |
| backache | dolor de espalda |
| Backbeat | Backbeat |
| backbite | calumniar |
| backbiter | calumniador |
| backbiting | difamación |
| backbone | espina dorsal |
| backbreaking | agotador |
| Backcountry skiing | Freeride |
| backdate | antedatar |
| backdated | antedatado |
| Backdated to | Rappel |
| Backdraft | Backdraft |
| backdrop | telón de foro |
| backed | con respaldo |
| backer | fiador |
| backfire | petardear |
| backgammon | juego de chaquete |
| background | fondo |
| background information | información de fondo |
| background level | nivel de base |
| background music | música de fondo |
| background noise | ruido de fondo |
| background process | proceso de fondo |
| background program | programa subordinado |
| background radiation | radiación de fondo |
| backhand | revés |
| backhand stroke | revés |
| backhander | revés |
| backing | apoyo |
| backlash | rebote |
| backless | sin espalda |
| backlit | retroiluminado |
| backlock | rezago |
| backlog | atrasos |
| Backmasking | Backmasking |
| backpack | mochila |
| backpacker | mochilero |
| backpedal | echarse atrás |
| Backpropagation | Propagación hacia atrás |
| backroom | apartado |
| backs | defensa |
| backscratcher | rascaespalda |
| backseat | asiento trasero |
| backside | parte posterior |
| backslash | barra inversa |
| backslide | recaer |
| backsliding | reincidencia |
| backspace | tecla de retroceso |
| backsplash | salpicadero |
| backstage | entre bastidores |
| backstairs | escalera de servicio |
| backstory | historia de fondo |
| Backstreet Boys | Backstreet Boys |
| backstroke | dorso |
| backtrack | retroceder |
| backtracking | exploración hacia atrás |
| backup | resguardo |
| backup file | archivo de seguridad |
| backup light | luz de retroceso |
| Backus-Naur form | Backus-Naur form |
| backward | a popa |
| backward compatibility | retrocompatibilidad |
| backward compatible | retrocompatible |
| Backward message | Backmasking |
| Backward pawn | Peón retrasado |
| backwardly | atrasado |
| backwardness | barbarie |
| backwards | a popa |
| backwash | repercusión |
| backwater | remanso |
| backwoods | región salvaje |
