1. (n.) An instrument used in weaving for passing or shooting the thread of the woof from one side of the cloth to the other between the threads of the warp.

2. (n.) The sliding thread holder in a sewing machine, which carries the lower thread through a loop of the upper thread, to make a lock stitch.

3. (n.) A shutter, as for a channel for molten metal.

4. (v. i.) To move backwards and forwards, like a shuttle.

Amtrak air transport air travel airfreight alternate back and fill baggage train battledore and shuttlecock cable railroad choo-choo cog railroad cog railway come and go commute ebb and flow el electric electric train elevated express express train flier freight freight train freighter funicular goods train hand loom hitch and hike interurban knitting machine lightning express limited local loom metro metronome milk train monorail oscillator parliamentary parliamentary train pass and repass passenger train pendulum rack-and-pinion railroad railroad train range rattler reciprocate ride and tie rocker rocking chair rocking stone rolling stock seesaw shunt shuttle service shuttle train shuttlecock special streamliner subway swing teeter teeter-totter teeterboard teetery-bender to-and-fro train tube underground vibrator wax and wane way train weaver wibble-wabble wigwag zigzag