One that indicates or foreshadows what is to come; a forerunner.
tr.v.har·bin·gered, har·bin·ger·ing, har·bin·gers
To signal the approach of; presage.
[Middle English herbengar, person sent ahead to arrange lodgings, from Old French herbergeor, from herbergier, to provide lodging for, from herberge, lodging, of Germanic origin; see koro- in Indo-European roots.]
indicant, indication – something that serves to indicate or suggest; “an indication of foul play”; “indications of strain”; “symptoms are the prime indicants of disease”