hap·py 
/ˈhæpi/ adjective
hap·pi·er; hap·pi·est /ˈhæpi/ adjective 1 a : feeling pleasure and enjoyment because of your life, situation, etc.
▪ She was a very happy child. ▪ I can see that you're not happy in your work. [=I can see that you do not enjoy your work] ▪ You don't look happy. What's the problem? ▪ We're all one big, happy family here. ▪ I'd do anything to make/keep her happy. ▪ She's happy playing with her toys. = She's happy when she plays with her toys.
b : showing or causing feelings of pleasure and enjoyment
▪ I could hear the children's happy laughter in the other room. ▪ She had a very happy childhood. ▪ They've had a very happy marriage. ▪ remembering happier times ▪ a happy event/occasion ▪ I was glad the movie had a happy ending.
c not used before a noun : pleased or glad about a particular situation, event, etc.
▪ We are so happy that you were able to come to the party. ▪ They are not at all happy about the rise in taxes. ▪ He's not happy with the way the project is going. ▪ It's great that he won the scholarship. I'm very happy for him. [=I am glad something good happened to him]
d : very willing to do something — usually followed by to + verb ▪ I would be happy to assist you. 2 — used as part of a greeting or wish for someone on a special holiday or occasion ▪ Happy birthday, Mom! ▪ Happy Holidays! 3 always used before a noun : lucky or fortunate
▪ We were brought together by a series of happy accidents. ▪ a happy coincidence 4 always used before a noun : fitting or suitable
▪ a happy choice of words ▪ He was a happy choice for chairman of the committee.
▪ She was a very happy child. ▪ I can see that you're not happy in your work. [=I can see that you do not enjoy your work] ▪ You don't look happy. What's the problem? ▪ We're all one big, happy family here. ▪ I'd do anything to make/keep her happy. ▪ She's happy playing with her toys. = She's happy when she plays with her toys.
b : showing or causing feelings of pleasure and enjoyment
▪ I could hear the children's happy laughter in the other room. ▪ She had a very happy childhood. ▪ They've had a very happy marriage. ▪ remembering happier times ▪ a happy event/occasion ▪ I was glad the movie had a happy ending.
c not used before a noun : pleased or glad about a particular situation, event, etc.
▪ We are so happy that you were able to come to the party. ▪ They are not at all happy about the rise in taxes. ▪ He's not happy with the way the project is going. ▪ It's great that he won the scholarship. I'm very happy for him. [=I am glad something good happened to him]
d : very willing to do something — usually followed by to + verb ▪ I would be happy to assist you.
▪ We were brought together by a series of happy accidents. ▪ a happy coincidence
▪ a happy choice of words ▪ He was a happy choice for chairman of the committee.
(as) happy as a clam — see 1clam
happy medium — see 1medium
happy returns — see 2return
— see also trigger-happy
