a narrow walkway, especially one high above the surrounding area, used to provide access or allow workers to stand or move, as over the stage in a theater, outside the roadway of a bridge, along the top of a railroad car, etc.
a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.
a chattering or flighty, light-headed person.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a scrap or morsel of food left at a meal.
a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.
1885, "long, narrow footway," from cat + walk; in ref. to such narrowness of passage one has to cross carefully, as a cat walks. Originally of ships and theatrical back-stages. Application to fashion show runways is mid-20c.