pacer

plural pacers

1. One who paces.
2. In harness racing, a horse with a gait in which the front and back legs on one side take a step together alternating with the legs on the other side; as opposed to a trotter.
3. archaicA horse whose natural gait is a pace (where the legs of the same side are lifted together).

   And the hill-king spake to his footpages twain. Time with me goes slow. — "Put ye the gray pacers now unto the wain," But that grief is heavy I know.

   1828, Thomas Keightley, The Fairy Mythology, volume I, London: William Harrison Ainsworth, page 175

4. A pacemaker (one who sets the pace in a race).
5. A timer in an electric toothbrush that indicates how long the user should spend brushing in each part of the mouth.

plural pacers

1. AustraliaA mechanical pencil.

plural Pacers

1. rail transportA British lightweight railbus diesel multiple unit of class 140, 141, 142, 143 or 144.

alternative Australian British English New Zealand variant Pacer

1. USabbreviationacronymlawAcronym of Public Access to Court Electronic Records, an electronic public access service for United States federal-court documents.