In the more recent history of coal-mining the pit-hill was the mound of waste close to the pit-head, of little value perhaps but scratched over for small pieces of coal in hard times.
The verb meant to make level or smooth and it occurs in the inventories of goldsmiths, in contexts which suggest that metal was flattened on a small anvil by blows from a special hammer.
In early uses of this word the references are to placing plants in the ground or to establishing settlements of people overseas, as in Ireland and New England. As a word for a new wood of planted trees it is recorded from 1669 (OED).
A rare word, for which the OED offers two possible meanings, either a lock in which the works are pivoted on an iron plate or one for an outside door, encased in wood.