irritant, stumbling block, nemesis, whipping boy, achilles heel, bugbear, bane, impediment, headache, tussles, detractor, obstacle, hindrance, flashpoint, problem, admirer, foe, chink, hot potato, trump card, contributor, stalwart, bogeyman, apologist, lightning rod, mainstay, undoing, loggerheads, scar, boon, blemish, bugaboo, ointment, saving grace, warpath, punching bag, lapdog, setback, quandary, cross hairs, nightmare, albatross, millstone, softie, basher, embarrassment, lumps, craw, supporter, cog, irk, cause celebre, dent, biter, scalp, tangle, hater, peskier, spats, obduracy, mouthpiece, chagrin, dilemma, burr, hurdle, enigma, pains, bogy, handmaiden, pushover, sacred cow, slayer, tormentor, darling, troublemaker, fiercest, meddler, ruffle, lynchpin, hypocrites, claws, antagonist, enforcer, haunt, anathema, talisman, obeisant, trouble, linchpin, irritation, cahoots, wart, pimple, battle, rivalry, gadfly, kryptonite, scapegoat, fulcrum, pickle, cosh, thorns, vine, snag, cross, ghost, witch, hawthorn, holly, mountain, temptation, grudge, rose, spill, volcano, willow, acacia, bamboo, blot, bramble, thorny, laurel, hazel, blackthorn, ivy, oak, withered, leafless, cedar, gnarled, pomegranate, chaparral, leafy, myrtle, plum, chestnut

acanthoid, acanthous, bristlecone pine, crataegus, crown of thorns, datura, genus crataegus, genus datura, hickory pine, pinus aristata, pinus pungens, prickle, prickly pine, rocky mountain bristlecone pine, spinous, stunted, table-mountain pine

aculeus, annoyance, bother, botheration, nuisance, pain, pain in the ass, pain in the neck, rune, runic letter

spine