an instrument for drawing large circles or arcs, consisting of a horizontal beam along which two vertical legs slide
Also called: trammel
beam compass in American English
noun
Drawing
a compass having adjustable legs, set perpendicular to the paper and sliding along a horizontal bar so as to permit the drawing of large circles
Word origin
[1775–85]This word is first recorded in the period 1775–85. Other words that entered Englishat around the same time include: Americanism, amateur, backfire, flashing, pinafore