T square

American  

noun

1. a T -shaped ruler, used primarily in mechanical drawing, having a short crosspiece that slides along the edge of the drawing board as a guide to the perpendicular longer section in making parallel lines, right angles, etc., and as a support for triangles.

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T-square British  

noun

1. a T-shaped ruler used in mechanical drawing, consisting of a short crosspiece, which slides along the edge of the drawing board, and a long horizontal piece: used for drawing horizontal lines and to support set squares when drawing vertical and inclined lines

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Etymology

Origin of T square

First recorded in 1775–85

Example Sentences

At war's beginning, Puleston laid aside his brushes and went back to the drawing board with a T square.

From Time Magazine Archive

And out on the Margaritaville scene, the military was the only presence with the posture of a T square.

From Time Magazine Archive

We’ll each make a flying craft/object/thing out of clay, and then we’ll have a contest to see whose flings the farthest across the room off of a big metal T square mounted to his desk.

From "Popcorn" by Rob Harrell

Where the measures vary in length the ruling will most readily be done in light pencil with a T square, and afterwards inked.

From How to Write Music Musical Orthography by Harris, Clement A.

Well, my Apollo of the T square, pourquoi cet honneur?

From Peter Ibbetson by Du Maurier, George