A sign, indication, omen, or symptom that suggests something (e.g., the onset of an illness or a developing trend).
熱や咳は病気の兆候かもしれない。
A fever and cough may be signs of illness.
経済回復の兆候が見え始めた。
Signs of economic recovery have begun to appear.
彼の態度の変化は何か問題がある兆候だ。
His change in behavior is a sign that something is wrong.