from
The Collaborative International Dictionary of English v.0.48
Proviso \Pro*vi"so\, 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]