/ ˈʃæklz; NAmE / noun [ pl. ]
1.
two metal rings joined together by a chain and placed around a prisoner's wrists or ankles to prevent them from escaping or moving easily
2.
shackles (of sth) ( formal ) a particular state, set of conditions or circumstances, etc. that prevent you from saying or doing what you want :
a country struggling to free itself from the shackles of colonialism