THESAURUS
stick at
back down, balance, blench, boggle, debate, deliberate, demur, falter, fear, fight shy of, flinch, hang back, hang off, have qualms, hem and haw, hesitate, hold off, hover, hum and haw, jib, make bones about, pause, ponder, pull back, quail, recoil, retreat, scruple, shilly-shally, shrink, shy, shy at, stickle, stop to consider, straddle the fence, strain, strain at, think twice about, waver, wince, withdraw, yield
ROGET THESAURUS
stick at
Unwillingness
VB
be unwilling, nill, dislike, grudge, begrudge, not be able to find it in one's heart to, not have the stomach to, demur,
stick at, scruple, stickle, hang fire, run rusty, recoil, shrink, swerve, hesitate, avoid, oppose, dissent, refuse.
Difficulty
VB
be difficult, run one hard, go against the grain, try one's patience, put one out, put to one's shifts, put to one's wit's end, go hard with one, try one, pose, perplex, bother, nonplus, gravel, bring to a deadlock, be impossible, be in the way of, meet with difficulties, labor under difficulties, get into difficulties, plunge into difficulties, struggle with difficulties, contend with difficulties, grapple with difficulties, labor under a disadvantage, be in difficulty, fish in troubled waters, buffet the waves, swim against the stream, scud under bare poles, Have much ado with, have a hard time of it, come to the push, come to the pinch, bear the brunt, grope in the dark, lose one's way, weave a tangled web, walk among eggs, get into a scrape, bring a hornet's nest about one's ears, be put to one's shifts, flounder, boggle, struggle, not know which way to turn, perdre son Latin,
stick at, stick in the mud, stick fast, come to a stand, come to a standstill, come to a deadlock, hold the wolf by the ears, hold the tiger by the tail, render difficult, enmesh, encumber, embarrass, ravel, entangle, put a spoke in the wheel, lead a pretty dance.
Doubt
VB
disbelieve, discredit, not believe, misbelieve, refuse to admit, refuse to believe, doubt, be doubtful, doubt the truth of, be skeptical as to, diffide, distrust, mistrust, suspect, smoke, scent, smell a rat, have doubts, harbor doubts, entertain doubts, suspicions, have one's doubts, demure,
stick at, pause, hesitate, scruple, stop to consider, waver, hang in suspense, hang in doubt, throw doubt upon, raise a question, bring in, call in question, question, challenge, dispute, deny, cavil, cause a doubt, raise a doubt, start a doubt, suggest a doubt, awake a doubt, make suspicion, ergotize, startle, stagger, shake one's faith, shake one's belief, stagger one's faith, stagger one's belief.