thankless
adjective
- unthankful/ungrateful (not moved by or expressing gratitude)
Wiktionary
adj
Etymology: From Middle English thankles, equivalent to thank + -less.
- Not appreciated or rewarded.
“One indispensable and thankless Unesco task is organizing tsunami warnings systems and pushing for tsunami education on risky shores around the world.”
“In a raucous atmosphere, it was an unforgiving and physical contest from the start. Grant Hanley conceded the first free-kick within the opening 20 seconds, setting the tone for a busy and thankless evening for Serbian referee Milorad Mazic.”
- Ungrateful or unappreciative.