Firth Muir # KCQ V NO468065 2 145m
Firthmure 1592 RMS v no. 2100 [common pasture, and right to take fuel, fail and divot in Firth Muir]
terras nuncupatas lie Firthmur 1594 RMS vi no. 120 [Forbes of Rires; ‘lands called the Firth Muir’, part of barony of Rires KCQ]
terris nuncupatis Firthmure 1610 Retours (Fife) no. 218 [barony of Rires]
Firthmure 1643 Retours (Fife) no. 664 [see Balniel KCQ]
de Firthmuire 1669 Retours (Fife) no. 1054 [‘with freedom to take fuel from Firth Muir’ (cum libertate focalium de Firthmuire)]
N. Firthmoor 1775 Ainslie/Fife [at about NO468066]
S. Firthmoor 1775 Ainslie/Fife [at about NO468063]
the Furthmuir 1802 Sasines no. 6141
<F>rithfield 1827 Ainslie/East Fife [Erithfield clearly an error for Frithfield]
The Firth Muir 1849 RHP5352 [title of plan by T. Marr]
Sc fyrth + Sc muir
‘Land overgrown with brushwood, scrubland on the edge of forest’. See Elements Glossary PNF 5, s.v. The word is found further east, in Frithfield KRY. A small settlement, now gone, which appears as Muiredge on Roy (1753) and Mooredge on Ainslie/Fife (1775), defines the northern edge of this muir.
RHP5352 (1849) shows Firth Muir, with a large coalpit and a whinstone quarry, west of the turnpike road from Balcarres to Cupar, marching with the lands of Balniel (Balneel) and Kilbrackmont (Kilbrakmont) on east, Lathallan on north and west, and Lathallan Mill on south (all KCQ).
This place-name appeared in printed volume 3