in slang phrase
gin up "enliven, make more exciting," 1887, probably from earlier
ginger up in same sense, from
ginger in sense of "spice, pizzazz;" specifically in ref. to the treatment described in the 1811 slang dictionary under the entry for
feague:
... to put ginger up a horse's fundament, and formerly, as it is said, a live eel, to make him lively and carry his tail well; it is said, a forfeit is incurred by any horse-dealer's servant, who shall shew a horse without first feaguing him. Feague is used, figuratively, for encouraging or spiriting one up.