This is the 5487th most frequent Japanese word.
うれし
"うれし" means "happy" or "glad."
Here, 'うれし' (happy) is used to describe a positive emotional state related to experiences.
今日はうれしいことがたくさんありました。
Today, many happy things happened.
Here, 'うれし' is combined with 'くなる', indicating the onset of feeling happiness due to a specific reason.
君の成功を聞いて、うれしくなりました。
Hearing about your success made me happy.
In this sentence, 'うれし' is expressed as '嬉しい', depicting happiness stemming from receiving a present.