Yugo or yuko was the second lowest score that could be achieved in a judged match, the score corresponding to five judo points. Since the new rules, a Yuko is a Waza-Ari.
This score was achieved if a technique was performed reasonably and the opponent came to his side. Judged the judoka on his back and the technique was performed well than was (still) given a ippon, also called a full point. A yuko also appeared on the scoreboard when the opponent got his second shido, this was a punishment.
wiki
