Of bad omen; inauspicious; indicating or seeming likely to bring bad luck. A common idiomatic expression.
黒猫が目の前を横切ると縁起が悪いと言う人もいる。
Some people say it's bad luck if a black cat crosses in front of you.
鏡が割れてしまって、今日は縁起が悪い気がする。
The mirror broke, and I feel like today is unlucky.
結婚式の前にトラブルが続いて、縁起が悪いと心配した。
Troubles kept happening before the wedding, and we worried it was a bad omen.