Other forms: unleashed, unleashing, unleashes
To unleash is to let something powerful loose. Unleash a storm, unleash the potential, unleashed on the world.
The literal sense is releasing a dog from its lead, and everything else follows from that image — unleashing a force means removing what was holding it. It is heavily used in business and political rhetoric: unleash growth, unleash innovation, which is why it has worn thin. Note leash; and that what is unleashed is always powerful, or the word would not be worth using.
1verbunleashTo let something powerful loose.
“The storm unleashed heavy rain and strong winds along the whole coast.”
unleash is a releasing.
Middle English
leesshe
English
leash
English, today
unleash
Built from
From un- + leash. leash comes from Middle English leesshe, leysche, lesshe, a variant of more original lease, from Middle English lees, leese, leece, lese, from Old French lesse (modern French laisse), either from Latin laxa, feminine form of laxus (“loose”) or, more probably, from a deverbal of Old French lesser, laissier, from Latin laxō (“loose”); compare lax. a doublet of laisse.
Etymology from Wiktionary, CC BY-SA