Fine cord of a fibrous material, such as cotton or flax, made of two or more filaments twisted together and used in needlework and the weaving of cloth. A piece of such cord. A thin strand, cord, or filament of natural or manufactured material. Something that suggests the fineness or thinness of such a strand, cord, or filament: a thread of smoke. Something that suggests the continuousness of such a strand, cord, or filament: lost the thread of his argument. A helical or spiral ridge on a screw, nut, or bolt. Computer Science A portion of a program that can run independently of and concurrently with other portions of the program. Computer Science A set of posts on a newsgroup, composed of an initial post about a topic and all responses to it. Slang Clothes. To pass one end of a thread through the eye of (a needle, for example). To pass (something) through in the manner of a thread: thread the wire through the opening. To pass a tape or film into or through (a device): thread a film projector. To pass (a tape or film) into or through a device. To connect by running a thread through; string: thread beads. To make one's way cautiously through: threading dark alleys. To make (one's way) cautiously through something. To occur here and there throughout; pervade: "More than 90 geologic faults thread the Los Angeles area\u201d ( Science News). To machine a thread on (a screw, nut, or bolt). To make one's way cautiously: threaded through the shoals and sandbars. To proceed by a winding course. To form a thread when dropped from a spoon, as boiling sugar syrup.