· jolly
· jovial
· joyful
· joyous
· jubilant
· kind
· kindhearted
· kindly
· klutzy
· knobby
There are no adjectives that begin with the letter k that mean to be thankful.
jitterykindheartedmagnificentnaughtyoptimisticquestionableunderstandingwisexenophobiczesty
kaleidoscopic
Kaki
* kind
KOOL
· knowledgeable
* knowledgeable
kiddy
· kind
kiddy
kinship