double-blind
dou ble-blind ▶adjective denoting a test or trial, esp. of a drug, in which any information that may influence the behavior of the tester or the subject is withheld until after the test. Compare with single-blind.
double-blind ▶adjective denoting a test or trial, especially of a drug, in which any information which may influence the behaviour of the tester or the subject is withheld until after the test.
The Wordsmith Dictionary
The Wordsmith Dictionary