IPA: /ˈθæŋk.fəl.ɪst/
KK: /θæŋkflɪst/
Feeling or showing gratitude; expressing appreciation for something received.
She was the thankfullest person at the party, always expressing her gratitude to everyone.
Comparative: more thankful
Superlative: thankfullest
Thankfullest → It is formed from "thank" (from Old English *þanc*, meaning gratitude or appreciation) and "-ful" (meaning full of) and "-est" (a superlative suffix indicating the highest degree). The word "thankfullest" means the most full of gratitude or appreciation.
Think of being 'full of gratitude' — 'thank' means appreciation, and '-ful' means full, while '-est' indicates the highest level. This helps you remember that 'thankfullest' means the most grateful.
No commonly confused words.