The Collaborative International Dictionary of English v.0.48:
Prodromal \Prod"ro*mal\, a. (Med.) Of or pertaining to prodromes; as, the prodromal stage of a disease. [1913 Webster]WordNet (r) 3.0 (2006):
prodromal adj 1: symptomatic of the onset of an attack or a disease [syn: prodromal, prodromic]