utmost:greatest possible; greatest; highest
unanimous:in the complete accord or agreement; agreed
undertake:set about; try; attempt
ultimatum:final offer or demand given with the threat of severe penalties if refused.
uncanny:strange and mysterious
undaunted:not afraid; not discouraged; fearless
undermine:weaken by secret or unfair means
unrest:lack of ease and quiet; restlessness
yelp:the quick, sharp bark or cry of a dog, fox, etc.
yonder:within sight but not near; over there
yowl:long, distressful or dismal cry
zealot:person who shows too much zeal
zeal:eager desire in going for a goal
strange and mysterious
weaken by secret or unfair means
final offer or demand given with the threat of severe penalties if refused.