1. A very small twist of flax, wool, cotton, silk or other fibrous substance, drawn out to considerable length.

2. The filament of a flower.

3. The filament of any fibrous substance, as of bark.

4. A fine filament or line of gold or silver.

5. Air-threads,the fine white filaments which are seen floating in the air in summer, the production of spiders.

6. Something continued in a long course or tenor; as the thread of a discourse.

7. The prominent spiral part of a screw.