a.

1. （感到）高興的；樂意的[F][（+at/about）][+to-v][+that]
   I am happy to accept your invitation.

   我很高興接受你的邀請。

2. 滿足的；滿意的[F][（+about/with）]
   He won't be happy with the result.

   他對結果不會滿意。

3. 幸運的；幸福的[B]
   Their marriage has been a very happy one.

   他們的婚姻非常美滿。

4. （言行等）恰當的；巧妙的
   A happy thought struck her.

   她突然想到一個好主意。

5. （用於祝詞）快樂的[B]
   Happy birthday to you!

   祝你生日快樂！

adj.

1. feeling or showing pleasure or contentment.
   ▸willing to do or accept something.
2. fortunate and convenient:
   a happy coincidence.
3. [in combination] informal inclined to use a specified thing excessively or at random:
   trigger-happy.