Jealous, jaundiced, jubilant, joyous, judicial, jaded, joker, jolly, joyful
jolly, joyful, jealous jovial, juvenile
kind
Unique.
kind
Independent.
kindness
rough.
rough.
One personality trait that starts with "Y" is youthful, which describes someone who exhibits the characteristics or energy typical of youth or being young.
=Self-discipline=
Jovial
a tragic flaw