half birthday

The day halfway in between two consecutive birthdays.

Japanese Meaning

二つの連続する誕生日の中間に位置する日、つまり前の誕生日と次の誕生日の間の日

We decided to celebrate his half birthday with a small cake and balloons.

私たちは彼の生後半年のお祝いを小さなケーキと風船で祝うことにしました。

Sense（1）

The day halfway in between two consecutive birthdays.

You can sing "Happy Half Birthday to You!" or you could try only singing every other word.

half birthdays

（ plural ）