Definition of "unprepossessing"

One of these unseen observers, a gentleman, was youthful, and had an air of high breeding and refinement, and a face marked with intellect, though otherwise of unprepossessing aspect.

1838, Nathaniel Hawthorne, Sylph Etherege

She drew up a chamois-skin bag, of an unprepossessing mouse colour, and emptied out a roll of bills.

1902, Myrtle Reed, chapter 4, in At the Sign of the Jack O'Lantern

In a review of operating experience with the Southern Region diesel-electric multiple-units on the Hastings line, read to the Institution of Locomotive Engineers in October, Mr. W. J. A. Sykes, Mechanical & Electrical Engineer of the S.R., revealed how the somehat unprepossessing appearance of these train sets came about.

1960 December, “The Hastings Line diesel-electric multiple units”, in Trains Illustrated, page 732

Sometimes movies with the most unprepossessing titles can surprise you. Case in point: “Monster Trucks,” a spry, spirited and delightful family film.

2017 January 12, Andy Webster, “Movie Review: Horses Under the Hood?”, in New York Times, retrieved 15 January 2017