I suspect that your 'G' is wrong. A crossword-solving site suggests 'boot' and, although I couldn't see it myself, a web search shows that 'boot' is an obsolete word for 'advantage'. So it appears to be a double definition.
A crossword-solving site suggests 'boot' and, although I couldn't see it myself, a web search shows that 'boot' is an obsolete word for 'advantage'. So it appears to be a double definition.