GNU Collaborative International Dictionary of English

Found one definition

1.       
   Proviso , n.; pl. Provisos . [L., (it) being provided, abl. of provisus, p. p. of providere. See Provide, and cf. Purview.] An article or clause in any statute, agreement, contract, grant, or other writing, by which a condition is introduced, usually beginning with the word provided; a conditional stipulation that affects an agreement, contract, law, grant, or the like; as, the contract was impaired by its proviso.
   1913 Webster
   He doth deny his prisoners,
   But with proviso and exception.
   Shak.
   
   1913 Webster