The Collaborative International Dictionary
Unsight unseen
Unsight \Un*sight"\, a. Doing or done without sight; not seeing or examining.
Unsight unseen, a colloquial phrase, denoting unseeing unseen, or unseen repeated; as, to buy a thing unsight unseen, that is, without seeing it.
For to subscribe, unsight, unseen,
To a new church discipline.
--Hudibras.
There was a great confluence of chapmen, that
resorted from every part, with a design to purchase,
which they were to do ``unsight unseen.''
--Spectator.
Wiktionary
unsight unseen
a. (dated form of sight unseen English)