noun

1. any circumstance, event, or condition that accompanies something and indicates its existence or occurrence; sign; indication
2. Med. any condition accompanying or resulting from a disease or a physical disorder and serving as an aid in diagnosis

Etymology: altered (infl. by LL or Gr) < ME symthoma < ML sinthoma < LL symptoma < Gr symptōma, anything that has befallen one, casualty < sympiptein, to fall together, happen < syn-, together + piptein, to fall: see feather