Merriam-Webster's Dictionary and Thesaurus - Merriam-Webster [1467]
under way adverb 1 : into motion from a standstill
2 : in progress
un·der·wear noun : clothing or a garment worn next to the skin and under other clothing
un·der·weight adjective : weighing below what is normal, average, or necessary
— underweight noun
un·der·world noun 1 : the place of departed souls : HADES
2 : the side of the world opposite to one
3 : the world of organized crime
un·der·write verb -wrote ; -writ·ten ; -writ·ing 1 : to write under or at the end of something else
2 : to set one's name to an insurance policy and thereby become answerable for a designated loss or damage
3 : to subscribe to : agree to
4 : to guarantee financial support of
— un·der·writ·er noun
Synonyms
capitalize, endow, finance, fund, stake, subsidize—more at FINANCE
un·de·sign·ing adjective : having no artful, ulterior, or fraudulent purpose : SINCERE
un·de·sir·able adjective : not desirable
— undesirable noun
un·de·sired adjective : not desired : UNWANTED
Synonyms
unasked, unbidden, uninvited, unsolicited, unsought, unwanted, unwelcome—more at UNSOUGHT
un·de·ter·mined adjective 1 : not yet definitely or authoritatively decided, settled, or fixed
2 : not bounded by definite limits or restrictions
3 : not determinate in form or character
Synonyms
open, pending, undecided, unresolved, unsettled—more at PENDING
un·de·vi·at·ing adjective : keeping a true course
Synonyms
steady, unchanging, uniform, unvarying, unwavering—more at UNIFORM
un·dies noun plural : UNDERWEAR; especially : women's underwear
un·di·lut·ed adjective : not diluted
Synonyms
absolute, fine, neat, plain, pure, refined, straight, unadulterated, unmixed—more at PURE
un·dis·turbed adjective : not disturbed
Synonyms
calm, collected, composed, cool, placid, self-possessed, serene, tranquil, unperturbed, unshaken, untroubled, unworried—more at CALM
un·di·vid·ed adjective : not divided
Synonyms
all, concentrated, entire, whole—more at WHOLE
un·do verb -did ; -done ; -do·ing 1 : to make or become unfastened or loosened
2 : to make null or as if not done : REVERSE
3 : to bring to ruin
4 : to disturb the composure of
Synonyms
[1] unbind, untie—more at UNTIE
[4] agitate, bother, concern, discompose, disquiet, distress, disturb, exercise, freak, perturb, unhinge, unsettle, upset, worry
un·doc·u·ment·ed adjective 1 : not supported by documentary evidence
2 : lacking documents required for legal immigration
un·do·ing noun : a cause of ruin
un·do·mes·ti·cat·ed adjective : not domesticated
Synonyms
feral, savage, unbroken, untamed, wild—more at WILD
un·doubt·ed adjective : not doubted or called into question : CERTAIN
un·doubt·ed·ly adverb : in an undoubted manner
Synonyms
certainly, definitely, doubtless, forsooth, incontestably, indeed, indisputably, really, surely, truly, undeniably, unquestionably—more at INDEED
1undress verb : to remove the clothes or covering of : STRIP
Synonyms
strip, unclothe; also bare, denude, divest, expose, uncover, unveil; bark, flay, peel, skin
Antonyms
dress, gown, robe
2undress noun 1 : informal dress; especially : a loose robe or dressing gown
2 : ordinary dress
3 : NUDITY
un·dressed adjective : not dressed
Synonyms
crude, native, natural, raw, unprocessed, unrefined, untreated—more at CRUDE
bare, naked, nude, unclad, unclothed—more at NAKED
un·due adjective 1 : not due
2 : exceeding or violating propriety or fitness : EXCESSIVE
un·du·lant adjective : rising and falling in waves
undulant fever noun : a human disease caused by bacteria from infected domestic animals or their products and marked by intermittent fever, chills, headache, weakness, and weight loss
un·du·late verb -lat·ed; -lat·ing [ORIGIN: LL undula small wave, fr. L unda wave]
1 : to have a wavelike motion or appearance
2 : to rise and fall in pitch or volume
un·du·la·tion noun 1 : wavy or wavelike motion
2 : pulsation of sound
3