The initial idioms of the letter G

gain ground against (something)	gain ground on
gain in	gain on
gain the upper hand	gain time
double-gaited	girl Friday
gala affair	gales of laughter
gall	gall and wormwood
let her go, Gallagher	gallery
gallery gods	gallivant around
gallop	gallop through
galloping	galloping dandruff
gallows humour	gal
galumph around	galumph
galvanize into action	gams
gamble	gamble away
gamble on	gambler