IPA: /ˈdʒɔɪfəlɚ/
KK: /ˈdʒɔɪfəlɚ/
Having or showing a greater amount of happiness or delight than usual.
The children were joyfuller than ever after receiving their gifts.
Comparative: joyfuller
Superlative: joyfullest
Joyfuller → It is formed from "joy" (from Old French *joie*, meaning happiness or delight) and "-ful" (meaning full of) and "-er" (a suffix used to form comparative adjectives). The word "joyfuller" means more full of joy or happiness than something else.
Think of 'joy' as happiness and remember that 'joyfuller' means more full of happiness.