guileless
GYLE-lisadjMeaning innocent and without tricks; open and honest
Memory hook GUILE-LESS: no tricks at all. Theo plays cards holding his hand face out so everyone can see it: no tricks, no secrets, no bluffing. He is guileless.
The puppy’s guileless eyes made it impossible to stay angry.
In context Unlike the sly older players, the new girl was guileless: she told everyone her strategy before the game and was surprised when they used it against her.
Similar innocent, naive, artless, trusting
Opposite sly, cunning, devious
From guile, “sly trickery,” + -less: without tricks.