inveterate, adj. 1. habitual, chronic, continuous, continual; confirmed, inured, hardened, hard-core, die-hard, dyed-in-the-wool.
2. ingrained, implanted, deep-seated, deep-rooted; fixed, rooted, riveted, set; entrenched, established, long-established, longstanding, of long standing; venerable, time-honored, immemorial, hallowed.
invidious, adj. 1. antagonistic, inimical, hostile, malicious, rancorous, vexatious, spiteful; adverse, provoking, troublesome, SI. bitchy, odious, hateful, unfriendly, unpopular; offensive, objectionable.
2. deleterious, injurious, harmful, hurtful; pernicious, baneful, baleful, malefic, maleficent, Obs. malefical, malign, malignant, mischievous; detrimental, damaging, destructive, internecine, disastrous, ruinous, prejudicial.
invigorant, n. bracer, tonic, cordial, stimulant, Inf. eyeopener, Inf. pick-me-up or pick-up; elixir, panacea, restorative, theriac, ptisan, Med. roborant.
invigorate, v. energize, fortify, strengthen; enliven, liven up, animate, pep up; stimulate, whet, motivate, inspirit, inspire, vivify, vitalize, quicken; galvanize, electrify, Inf. turn on, Inf. psych up, Inf. spark, Inf. sparkplug; jolt, jog, waken, wake up, shake up;
arouse, rouse, excite, fire or fire up, inflame.
invigorating, adj. stimulating, animating, enlivening, vivifying, vitalizing, bracing, invigorative; energizing, fortifying, strengthening; restorative, restoring, remedial, Med. analeptic; healthful, healthy, salubrious, salutary, salutiferous, tonic, wholesome.
invincible, adj. 1. unconquerable, invulnerable, impregnable, impenetrable, inviolable, indestructible, undestroyable, imperishable, undefeatable, unbeatable, unassailable; formidable, powerful, mighty, Literary, puissant; indomitable, insuppressible, stout, stout-hearted, stalwart, Archaic, stalworth, steadfast, doughty, hardy, solid, stable, tough, staunch, stanch, cast-iron, Inf. hard as a rock, Inf. tough as nails; firm, resolute, resolved, determined, intransigent, inflexible, adamant, adamantine; defiant, unyielding, unflinching, unwavering, unswerving, undeviating; persevering, unrelenting, relentless, irrepressible, indefatigable, untiring, tireless, weariless, unwearying, unflagging.
2. courageous, brave, valiant, valorous, heroic, hero-ical, hero-like, lionhearted, iron-hearted, great-hearted, high-hearted; virile, manly, manful; intrepid, fearless, dauntless, dreadless, aweless, unafraid, undaunted, unblenched, unblenching, undismayed, unappalled, unalarmed; bold, bold-spirited, high-spirited, daring, audacious; plucky, mettlesome, nervy, gritty, spirited, red-blooded, Inf. spunky, SI. gutsy.
3. insuperable, insurmountable, overwhelming, overpowering, overcoming, overmastering, overmatching; oppressive, burdensome, backbreaking, crushing, demoralizing, defeating.
inviolability, n. 1. inalienability, inviolacy, un-touchability; sacredness, sanctity, sacrosanctness, holiness.
2. invulnerability, impregnability, impenetrability, invincibility, indomitability, unconquerability; unassailableness, unattackableness, insuperability, insurmountability.
3. incorruptibility, uncorruptness, honesty, upstandingness, righteousness, virtuousness; loyalty, faithfulness, constancy, steadfastness, trueness, true-blueness; reliability, dependability, trustworthiness, Inf. trustiness.