午飯 is read as ごはん (gohan) and means lunch.
ごはん
gohan
ゆうはん
evening meal
ひるめし
lunch
あさめし
breakfast
めし
cooked rice
せきはん
red rice (beans and mochi) for auspicious occasions
ひるごはん
よるごはん
dinner
ごご
afternoon
ごぜん
morning
うま
fifth month of the lunar calendar
ごぜんちゅう
in the morning
ごぜんさま
coming home after midnight