English translation of '开怀'

形

1. happy
   ⇒ 乐开怀 (lè kāihuái) be extremely happy
   ⇒ 宴会上,大家开怀畅饮。 (Yànhuì shang, dàjiā kāihuái chàngyǐn.) At the dinner party everyone drank to their heart's content.