1) In the mining industries the meaning may have been similar to that of ‘to win’.
In 1694, a banksman wrote to his employer of gaining the field to your Honours advantage, Colsterdale.
2) Commonly used in connection with routes between two places, meaning ‘short’ or ‘convenient’.
A discussion about Bingley Bridge in 1683 touched on its status and the responsibility for its maintenance. The local constable described it as the direct cart or waine roade from Keighley to Bradford whereas the authorities claimed that it was only passable by horse or foote and went upp a hill to the moores, an obscure way not used by any strangers. It was argued that both Marloo bridge and Cottingley bridge were very neere as gaine as it is. The superlative was also popular: in 1616, William Fysher was accused of riding to Brandsby kepeing noe hye waye but breaking gappes at the gaynest . In some cases ‘convenient’ was ‘near’ and in 1778 the Honley surveyor of the highways was told to find all the stone as gain to the road as possible. It explains the minor place-names Gain Bank, Gain Lane and Gainest.