The following information is taken from the Dictionary of the Older Scottish Tongue, available online at http://www.dsl.ac.uk/index.html. This is a work in progress.
| Spelling | Number | Dates & headers |
|---|---|---|
| Forsyth | 2 | (deces); 1626 (burn) |
| Forsythe | 1 | 1565 (cutler) |