t 1 r 1 u 1 s 1 t 1 f 4 u 1 l 1
8 letters · 11 points in Scrabble
Meaning
adjective inclined to believe or confide readily; full of trust; - Nordhoff & Hall
originFrom Middle English trustful, trystefull, equivalent to trust + -ful.
Etymology from Wiktionary, CC BY-SA 3.0