Synonyms of the word 
UNAPPRECIATIVE → THANKLESS - UNGRATEFUL - UNTHANKFUL
unappreciative
- adj. Not appreciative.
thankless
- adj. (of a task) not appreciated or rewarded.
- adj. (of a person) ungrateful or unappreciative.
ungrateful
- adj. Not grateful; not expressing gratitude; a dissatisfied person.
unthankful
- adj. Not thankful; ungrateful.
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