Late 18th century (in an earlier sense). In sense 1 either from reposit, or shortened from repository.
reposit2
/rɪˈpɒsɪt/
verb
1[with object]To put (a thing) in a place, especially for storage or safe keeping; to repose, deposit.
2[with object]To restore to a place or position; especially (Surgery ) to restore to the normal position.
Origin
Mid 17th century; earliest use found in Henry Lord (b. 1563), clergyman and ethnographer. From classical Latin reposit-, past participial stem of repōnererepone.