To knock or twist a block of composed metal type out of alignment before it is securely locked up. When a form is squabbled, the individual characters lean, slide off their feet, or slip past their spacing material, requiring the compositor to painstakingly straighten the lines with a bodkin.
Heard on the job
Watch your sleeves around the imposing stone, you just squabbled three lines of the main text.
Insider tip
A squabbled form that goes unnoticed will print with crooked letters or missing characters where the type slipped below the printing height.