| backtrack |
to retrace one's previous route. [2 definitions] |
| backup |
an alternate, substitute, or copy kept in reserve. [4 definitions] |
| back up |
to create and store a copy of (a computer file), often in a separate location, in case the original is damaged or lost. [8 definitions] |
| backward |
in the direction of or to the rear or back. [8 definitions] |
| backward and forward |
in depth; completely; thoroughly. |
| backwards |
variant of "backward." |
| backwash |
in nautical terminology, water that an oar, propeller, or the like pushes toward the rear of a boat. [4 definitions] |
| backwater |
a pool of water that a dam, current, flood, or the like prevents from flowing. [2 definitions] |
| backwoods |
(often used with a sing. verb) an area that is mostly covered with trees and that has few inhabitants. [4 definitions] |
| backyard |
an open area behind a house that is part of the homeowner's property. |
| bacon |
a fatty, smoked, and salted form of pork, taken from the back and side of the pig. |
| bacteremia |
the presence of bacteria in blood. |
| bacteria |
pl. of bacterium. Bacteria are one-celled microscopic organisms of various shapes that are often agents of fermentation and putrefaction and that, in some cases, cause disease. |
| bactericide |
something that can kill bacteria. |
| bacteriology |
the science that is concerned with bacteria. |
| bacteriophage |
any virus that attacks and kills bacteria. |
| bacterium |
any of a large group of one-celled microscopic organisms of various shapes that are often agents of fermentation and putrefaction and that may cause disease. |
| Bactrian camel |
a two-humped camel that is native to central Asia and that is stockier and hairier than an Arabian camel. (Cf. dromedary.) |
| bad |
of low quality or desirability; unsatisfactory. [9 definitions] |
| bad apple |
one exceptional member of a group who behaves badly and causes trouble for all the other members of the group or makes the others look bad. |
| bad blood |
animosity between two or more people; mutual hostility. |