1. 释放；放纵…而出
If you say that someone or something unleashes a powerful force, feeling, activity, or group, you mean that they suddenly start it or send it somewhere.

1. release or vent

e.g. unleash one's anger

2. turn loose or free from restraint

e.g. let loose mines
Loose terrible plagues upon humanity

Synonym: let looseloose

3. release from a leash

e.g. unleash the dogs in the park