Definition of happy
: favored by luck or fortune : fortunate a happy coincidence
: notably fitting, effective, or well adapted : felicitous a happy choice
a : enjoying or characterized by well-being and contentment is the happiest person I know a happy childhood
b : expressing, reflecting, or suggestive of happiness a happy ending
c : glad, pleased I'm happy to meet you
d : having or marked by an atmosphere of good fellowship : friendly a happy office
a : characterized by a dazed irresponsible state a punch-happy boxer
b : impulsively or obsessively quick to use or do something trigger-happy
c : enthusiastic about something to the point of obsession : obsessed
education-conscious and statistic-happy — Helen Rowen
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’
1.1happy about Having a sense of trust and confidence in (a person, arrangement, or situation)
‘he was not happy about the proposals’https://en.oxforddictionaries.com/definition/happy
1.2happy with Satisfied with the quality or standard of.
‘I'm happy with his performance’
1.3with infinitive Willing to do something.
‘we will be happy to advise you’