Birthdaisy
Birthdaisy: A portmanteau (/pɔ rtˈmæntoʊ/ ( listen), /ˌpɔ rtmænˈtoʊ/) or portmanteau word, is the combination of birthday and Daisy all brought together to make one idealistic word for celebrating the birth of people called Daisy
A bunch of mates simultaneously yell out "Happy Birthdaisy" and surprises Daisy as she enters the room.