She had a very happy life.

a happy marriage/childhood/occasion

I have many happy memories from that time.

The story has a happy ending.

Those were the happiest days of my life.

It had been a gloriously happy time.

if you wish somebody a Happy Birthday, Happy New Year, etc. you mean that you hope they have a pleasant celebration

satisfied that something is good or right; not anxious

I don't know what you've done, but the boss isn't happy.

I said I'd go just to keep him happy.

Are you happy with that arrangement?

I'm not happy with his work this term.

She was happy enough with her performance.

If there's anything you're not happy about, come and ask.

I'm not too happy about her living alone.

I'm perfectly happy to leave it till tomorrow.

People seemed quite happy to help.

He will be more than happy to come with us.

We'd be only too happy to accept your invitation.

By a happy coincidence, we arrived at exactly the same time.

He is in the happy position of never having to worry about money.

suitable and appropriate for a particular situation

That wasn't the happiest choice of words.

LEARNit Dictionary