パパ
パパ · papa · JLPT N4 · noun
dad
👨 Sounds like English papa — a loanword, written in katakana
パパ is borrowed straight from Western papa, which is why it is written in katakana rather than kanji. Two identical syllables, pa + pa, the same baby-talk doubling as ママ (mama). It is the casual, child-friendly word next to the native お父さん.