忙しい (isogashii) means "busy." This い-adjective describes a state of having many things to do, whether it's work, studies, or other activities, leaving little free time. For example, "今日はとても忙しいです。" (Kyou wa totemo isogashii desu.) means "I am very busy today."

「忙しい」はする事が多い時に使います。例：今日は忙しいです。