Chapter Umbrosity to Un- of U by Webster's Dictionary (1913 Edition)

Un-
(Un-). [OE. un-, on-, the unaccented form of the accented prefix and- (cf. Answer); akin to D. ont-, G. ent-, OHG. int-, Goth. and-. See Anti-.] An inseparable verbal prefix or particle. It is prefixed: (a) To verbs to express the contrary, and not the simple negative, of the action of the verb to which it is prefixed; as in uncoil, undo, unfold. (b) To nouns to form verbs expressing privation of the thing, quality, or state expressed by the noun, or separation from it; as in unchild, unsex. Sometimes particles and participial adjectives formed with this prefix coincide in form with compounds of the negative prefix un- (see 2d Un-); as in undone meaning unfastened, ruined; and undone (from 2d un- and done) meaning not done, not finished. Un- is sometimes used with an intensive force merely; as in unloose.

Compounds of this prefix are given in full in their proper order in the Vocabulary.

Un-
(Un-). [OE. & AS. un-; akin to OFries. un-, D. on-, OS., OHG., & G. un-, Icel. o-, u- , Sw. o-, Dan. u-, W. an-, L. in-, Gr. Skr. an-, a-. &radic193. Cf. A- not In- not, No, adv.] An inseparable prefix, or particle, signifying not; in-; non-. In- is prefixed mostly to words of Latin origin, or else to words formed by Latin suffixes; un- is of much wider application, and is attached at will to almost any adjective, or participle used adjectively, or adverb, from which it may be desired to form a corresponding negative adjective or adverb, and is also, but less freely, prefixed to nouns. Un- sometimes has merely an intensive force; as in unmerciless, unremorseless.

I. Un- is prefixed to adjectives, or to words used adjectively. Specifically: —

(a) To adjectives, to denote the absence of the quality designated by the adjective; as, —

(b) To past particles, or to adjectives formed after the analogy of past particles, to indicate the absence of the condition or state expressed by them; as, —

Unabolishable
 Unabsolvable
 Unabsurd
 Unabundant
 Unaccordant
 Unadoptable
 Unadventurous
 Unaffable
 Unaffectionate
 Unafraid
 Unalliable
 Unallowablew
 Unalterable
 Unambiguous
 Unambitious
 Unamendable
 Un-American
 Unamusive
 Unangular
 Unanxious
 Unapocryphal
 Unapostolic
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Unapparent
 Unappeasable
 Unapplausive
 Unappreciable
 Unapprehensible
 Unapprehensive
 Unapproachable
 Unartificial
 Unartistic
 Unassailable
 Unattainable
 Unattentive
 Unauthentic
 Unavailable
 Unbailable
 Unbearable
 Unbeautiful
 Unbeliefful
 Unbelievable
 Unbeneficial
 Unbenevolent
 Unblamable
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Unblemishable
 Unblissful
 Unboastful
 Unbold
 Unbookish
 Unbounteous
 Unbribable
 Unbrotherly
 Unburdensome
 Unbusinesslike
 Unbusy
 Uncandid
 Uncanonical
 Uncaptious
 Uncareful
 Uncelestial
 Unceremonious
 Unchallengeable
 Unchangeable
 Unchary
 Unchastisable
 Uncheerful
 Uncheery
 Unchildish
 Unchivalrous
 Uncholeri
 Unchristianlike
 Uncircumspect
 Uncivic
 Unclassible
 Unclassic
 Unclassical
 Uncleanly
 Unclear
 Unclerical
 Unclerklike
 Unclose
 Uncloudy
 Unclubbable
 Uncoagulable
 Uncogitable
 Uncollectible
 Uncomic
 Uncommendable
 Uncommercial
 Uncommunicable
 Uncommunicative
 Uncompact
 Uncompanionable
 Uncompassionate
 Uncompellable
 Uncompetitive
 Uncomplaisant
 Uncompliant 
Uncomplimentary
 Unconcealable
 Unconcurrent
 Unconditionate
 Unconfinable
 Unconfutable
 Uncongealable
 Uncongenial
 Unconjugal
 Unconjunctive
 Unconquerable
 Unconsecrate
 Uncontainable
 Uncontaminate
 Uncontradictable
 Uncontrite
 Unconvenable
 Unconventional
 Unconversable
 Unconversant
 Unconvertible
 Uncoquettish
 Uncordial
 Uncorpulent
 Uncorrespondent
 Uncorruptible
 Uncorruptive
 Uncostly
 Uncounselable
 Uncountable
 Uncounterfeit
 Uncourteous
 Uncourtierlike
 Uncourtly
 Uncrafty
 Uncreatable
 Uncritical
 Uncrystalline
 Uncultivable
 Uncurious
 Uncustomary
 Undangerous
 Undaughterly
 Undead
 Unddeceivable
 Undecidable
 Undecipherable
 Undeclinable
 Undecomposable
 Undefinable
 Undelectable
 Undeliberate
 Undelightful
 Undeliverable
 Undemocratic
 Undemonstrable
 Undemonstrative
 Undeniable
 Underogatory
 Undescendible
 Undescribable
 Undesirable
 Undesirous
 Undescribable
 Undevout
 Undiaphonous
 Undiligent
 Undiminishable
 Undiscernible
 Undisciplinable
 Undiscordant
 Undiscoverable
 Undissolvable
 Undistinguishable
 Undividable
 Undivine
 Undomestic
 Undoubtful

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Undrainable
 Undramatic
 Undrinkable
 Undurable
 Unduteous
 Undutiful
 Unearnest
 Uneatable
 Unecclesiastical
 Unedible
 Unelaborate
 Unelective
 Unelusive
 Unemotional
 Unemphatic
 Unemployable