unreliable

  1. not worthy of reliance or trust

    Synonyms : undependable
    Antonyms : reliable
    Examples :
    • in the early 1950s computers were large and expensive and unreliable
  2. liable to be erroneous or misleading

    Synonyms : undependable
  3. dangerously unstable and unpredictable

    Synonyms : treacherous
    Examples :
    • an unreliable trestle
  4. lacking a sense of responsibility

upend

  1. become turned or set on end

    Type Of : overturn, tip over, tump over, turn over
    Examples :
    • the airplanes upended
  2. set, turn, or stand on end

    Type Of : lay, set, put, place, pose, position
    Examples :
    • upend the box and empty the contents

unspoilt

  1. not left to spoil

    Synonyms : good, unspoiled

unclad

  1. having removed clothing

    Synonyms : unappareled, unattired, undressed, ungarbed, ungarmented

upon

  1. On; -- used in all the senses of that word, with which it is interchangeable.

unconditional

  1. not conditional

    Synonyms : unconditioned
    Antonyms : conditional
    Examples :
    • unconditional surrender
  2. not modified or restricted by reservations

    Synonyms : categoric, categorical, flat
  3. not contingent; not determined or influenced by someone or something else

unique

  1. radically distinctive and without equal

    Synonyms : alone, unequaled, unequalled, unparalleled
    Examples :
    • Bach was unique in his handling of counterpoint
  2. the single one of its kind

    Synonyms : singular
    Examples :
    • the unique existing example of Donne's handwriting
    • a unique copy of an ancient manuscript
    • certain types of problems have unique solutions
  3. (followed by `to') applying exclusively to a given category or condition or locality

    Examples :
    • a species unique to Australia
  4. highly unusual or rare but not the single instance

    Examples :
    • spoke with a unique accent
    • had unique ability in raising funds
    • a frankness unique in literature
    • a unique dining experience

umpteen

  1. innumerable but many

    Synonyms : umteen

unconquerable

  1. incapable of being surmounted or excelled

    Synonyms : insuperable
  2. not capable of being conquered or vanquished or overcome

    Antonyms : conquerable
    Examples :
    • a tribute to his courage...and his unconquerable will
    • faced unconquerable difficulties

unfair

  1. not fair; marked by injustice or partiality or deception

    Synonyms : unjust
    Antonyms : fair
    Examples :
    • used unfair methods
    • it was an unfair trial
    • took an unfair advantage