| Counter (adv.) A prefix meaning contrary, opposite, in opposition |
| Counter (v. t.) One who counts, or reckons up |
| Counter (v. t.) A piece of metal, ivory, wood, or bone, used in reckoning, in keeping account of games, etc. |
| Counter (v. t.) Money |
| Counter (v. t.) A prison |
| Counter (v. t.) A telltale |
| Counter (v. t.) A table or board on which money is counted and over which business is transacted |
| Counter (adv.) Contrary |
| Counter (adv.) In the wrong way |
| Counter (adv.) At or against the front or face. |
| Geiger counter / Geiger-Muller counter counter tube that detects ionizing radiations |
| Geiger tube / Geiger-Muller tube an ionization chamber contained in a tube in a Geiger counter |
| Geiger / Hans Geiger German physicist who developed the Geiger counter (-) |