noun
first meal ceremony; 100-day celebration
A traditional Japanese ceremony held when a baby is about 100 days old, where the infant is symbolically fed solid food for the first time to wish for a lifetime of plentiful food.
お食い初めでは、赤ちゃんに食べさせる真似をします。
At the okuizome ceremony, we pretend to feed the baby.
お食い初めの料理には、鯛や赤飯など縁起の良いもの
The okuizome meal includes auspicious foods like sea bream and red rice.
百日祝い is another name for the same 100-day celebration, but お食い初め specifically refers to the first meal ritual within that celebration.
From お (honorific prefix) + 食い (stem of 食う, 'to eat') + 初め ('first'). The reading ぞめ is a rendaku form of 初め.