prodrome
Concise Oxford English Dictionary © 2008 Oxford University Press:
prodrome /ˈprəʊdrəʊm, ˈprɒdrəʊm/
▶noun Medicine an early symptom indicating the onset of illness.
– derivatives
prodromal adjective,
prodromic adjective.
prodromal adjective,
prodromic adjective.
– origin C17: from Fr., from mod. L. prodromus, from Gk prodromos ‘precursor’, from pro ‘before’ + dromos ‘running’.
'prodrome' also found in these Oxford entries:

