Unpalatable means unpleasant to eat, or hard to accept. Unpalatable food, an unpalatable truth, politically unpalatable.
The figurative sense is now the commoner: an unpalatable truth is one nobody wants to hear, and politically unpalatable means a policy is right and unsellable. The palate inside it is the roof of the mouth, taken as the seat of taste.
1adjectiveunpalatableUnpleasant to eat, or hard to accept.
“The hospital food was so unpalatable that most patients sent their plates back untouched.”
unpalatable is a quality.
From un- + palatable.
Etymology from Wiktionary, CC BY-SA