Noun

1. A just detectable amount
2. An indication that something has been present
3. A suggestion of some quality
4. A drawing created by superimposing a semitransparent sheet of paper on the original image and copying on it the lines of the original image
5. Either of two lines that connect a horse's harness to a wagon or other vehicle or to a whiffletree
6. A visible mark (as a footprint) left by the passage of person or animal or vehicle

Verb

1. Follow, discover, or ascertain the course of development of something
2. Make a mark or lines on a surface
3. To go back over again
4. Pursue or chase relentlessly
5. Discover traces of
6. Make one's course or travel along a path; travel or pass over, around, or along
7. Copy by following the lines of the original drawing on a transparent sheet placed upon it; make a tracing of
8. Read with difficulty