red thread, n. 1. A navigational line drawn through the body of a day, connecting rooms that do not know each other. 2. The impression left by 8,271 heel-strikes on institutional carpet, visible only to the walker. 3. (Textile) A single strand pulled from the selvedge of a larger fabric; once removed, the weave loosens but does not collapse. 4. (Cardiology) The faint pulse of continuity felt when a person carries the same unfinished sentence from one meeting into the next, changing only the faces it is offered to. 5. (Archaic) The belief that a day, however fragmented, is a single garment worn from morning until it is hung on the back of a chair at night.