early 15c. "causing bodily or mental discomfort, affording no comfort," from un- (1) "not" + comfortable (adj.). Intransitive meaning "feeling discomfort, ill-at-ease" is attested from 1796. Related: Uncomfortably.
the uncomfortable truth
grew uncomfortable beneath his appraising eye
this kind of life can prove disruptive and uncomfortable
an uncomfortable way of surprising me just when I felt surest
the teacher's presence at the conference made the child very uncomfortable
an uncomfortable day in the hot sun
an uncomfortable chair