Webster's Revised Unabridged Dictionary · 1913

Tab

Tab , noun

[Etymol. uncertain.]

1.
The flap or latchet of a shoe fastened with a string or a buckle.
2.
A tag. See Tag, 2.
3.
A loop for pulling or lifting something.
4.
A border of lace or other material, worn on the inner front edge of ladies' bonnets.
5.
A loose pendent part of a lady's garment; esp., one of a series of pendent squares forming an edge or border.
6.
a small projecting piece of a file folder, file card, or similar sheet used in a filing system, on which a notation is written to permit convenient search for the folder, card, etc.
7.
a bill or check for some purchase, as in a restaurant; as, the salesman will pick up the tab.
8.
a key on a typewriter or computer keyboard which advances the carriage or curser to the next (preset) tab position; -- used especially to type or print text or numbers in columns.