1. 1. 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.
   2. A piece of such cord.
2. 1. A thin strand, cord, or filament of natural or manufactured material.
   2. Something that suggests the fineness or thinness of such a strand, cord, or filament: a thread of smoke.
   3. Something that suggests the continuousness of such a strand, cord, or filament: lost the thread of his argument.
3. A helical or spiral ridge on a screw, nut, or bolt.
4. Computer Science.
   1. A portion of a program that can run independently of and concurrently with other portions of the program.
   2. A set of posts on a newsgroup, composed of an initial post about a topic and all responses to it.
5. threads Slang. Clothes.

1. 1. To pass one end of a thread through the eye of (a needle, for example).
   2. To pass (something) through in the manner of a thread: thread the wire through the opening.
   3. To pass a tape or film into or through (a device): thread a film projector.
   4. To pass (a tape or film) into or through a device.
2. To connect by running a thread through; string: thread beads.
3. 1. To make one's way cautiously through: threading dark alleys.
   2. To make (one's way) cautiously through something.
4. To occur here and there throughout; pervade: "More than 90 geologic faults thread the Los Angeles area" (Science News).
5. To machine a thread on (a screw, nut, or bolt).

1. To make one's way cautiously: threaded through the shoals and sandbars.
2. To proceed by a winding course.
3. To form a thread when dropped from a spoon, as boiling sugar syrup.

[Middle English, from Old English thrǣd.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.