synchromesh

syn chro mesh |ˈsiNGkrōˌmeSH ˈsɪŋkroʊˌmɛʃ | ▶noun a system of gear changing, esp. in motor vehicles, in which the driving and driven gearwheels are made to revolve at the same speed during engagement by means of a set of friction clutches, thereby easing the change. ORIGIN 1920s: contraction of synchronized mesh .

synchromesh

syn ¦chro |mesh |ˈsɪŋkrə (ʊ )mɛʃ | ▶noun [ mass noun ] a system of gear changing, especially in motor vehicles, in which the driving and driven gearwheels are made to revolve at the same speed during engagement by means of a set of friction clutches, thereby easing the change. ORIGIN 1920s: contraction of synchronized mesh .