Sign
Indication
noun, の adjective
An omen for the climate of things is a sign or indication of change. If there's an omen, there's going to be a sign as well.
ちょうこう
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
彼女は、私に下痢の兆候がきたと告げるやいなや、トイレに駆け込んでいった。
She told me that she had symptoms of diarrhea and rushed into the bathroom.