happy

Pronunciation: /ˈhapi/

Definition of happy

1feeling or showing pleasure or contentment:Melissa came in looking happy and excited [with clause]:we’re just happy that he’s still alive [with infinitive]:they are happy to see me doing well
(happy about) having a sense of trust and confidence in (a person, arrangement, or situation):he was not happy about the proposals
(happy with) satisfied with the quality or standard of:I’m happy with his performance
[with infinitive] willing to do something:we will be happy to advise you
[attributive] used in greetings:happy Christmas

2 [attributive] fortunate and convenient:he had the happy knack of making people like him

3 [in combination] informal inclined to use a specified thing excessively or at random:they tended to be grenade-happy

Phrases

(as) happy as a sandboy (or British Larry or North American a clam or vulgar slang a pig in shit): extremely happy.
happy hunting ground: a place where success or enjoyment is obtained: this should prove a happy hunting ground for those in search of a bargain
[originally referring to the optimistic hope of American Indians for good hunting grounds in the afterlife]

Middle English (in the sense 'lucky'): from the noun hap + -y¹

If an adjective ends in a consonant plus y, change the y to i when adding -er or -est: (happier, happiest).

Definition of happy in the US English dictionary