Wiktionary
preclinical
a. 1 (context medicine English) Describing the period of a disease before any symptoms appear 2 Describing a test or trial of a new pharmaceutical on animals (or in vitro) rather than on humans
WordNet
preclinical
adj. of or relating to the early phases of a disease when accurate diagnosis is not possible because symptoms of the disease have not yet appeared [syn: presymptomatic]
Usage examples of "preclinical".
My people tell me there’s a fifty-fifty chance the preclinical trials will fail.