impeach, v. 1. accuse, charge, indict, Law. arraign, Law. impute, incriminate, criminate, recriminate, Rare, implead; denounce, implicate, inculpate; blame, hold [s.o.] accountable or responsible, lay at [s.o.'sj door, point the finger at [s.o.]; (all in reference to culpability) allege, ascribe, attribute, assign, impute, lay. 2. challenge, question, call into question, impugn, assail, revile, attack; discredit, impair, deprecate, dis parage, belittle, SI. badmouth; stigmatize, brand, slur, asperse, cast aspersions on, malign, slander, defame, vilify; inveigh against, rail against, declaim against, fulminate against,

impeccable, adj. 1. faultless, correct, perfect, ideal, flawless; immaculate, spotless, unspotted, stainless, unblemished, clean, clear; complete, finished, absolute. 2. irreproachable, unerring, virtuous, upright, exemplary, aboveboard, unimpeachable, above suspicion, Fr. sans peur et sans reproche; blameless, inculpable, impeccant, incorrupt; innocent, pure, chaste, sinless, guiltless, undefiled, pure as the driven snow,

impecunious, adj. penniless, out of money, cleaned out, insolvent, bankrupt, Inf. broke, Inf. flat, Inf. flat-broke; embarrassed, Inf. pinched, Inf. short, SI. hard up, SI. strapped, out of pocket, without a penny or a nickel to one's name, without a sou; poor, poor as a church mouse, poor as Job's turkey, impoverished, poverty-stricken, destitute, down and out, unable to make ends meet, unable to keep the wolf from the door, needy, indigent, necessitous, penurious,

impede, v. obstruct, block, contravene, hinder, thwart, balk, inhibit, frustrate, foil, confound, bar; undermine, sabotage, spike, Inf. spike [s.o.'s] guns, Inf. throw a spike in the wheels or a monkey wrench into the works; prevent, preclude, forestall, obviate, deter; stand in the way, interfere, interrupt, intervene, intercept, Inf. short-circuit; restrict, restrain, tie up, cramp, hamper, handicap, encumber, cumber, entangle, checkmate, stymie, tree, corner; set or put back, delay, stave or ward off, stop or dam up, clog, choke, hold back, Inf. bottleneck; turn aside, avert, counteract, offset, neutralize, countercheck; check, stay, arrest, put the breaks on, put a stop to, repress, nip in the bud.

impediment, n. 1. hindrance, encumbrance, obstacle, obstruction, stumbling block, road block; knot, hitch, curb, clog, bit, tether; inhibition, restriction, determent, damper, restraint; bar, barrier, block, counteraction, embargo, stricture, blockade; opposition, objection, discouragement, difficulty, drawback, disadvantage; delay, hang-up, snag, bottleneck, red tape; interference, setback, drag; load, burden, deadweight. 2. stammer, stutter, lisp, hesitance, hesitation, falter, speech defect,

impedimenta, n. equipment, supplies, materiel, traps, trappings, gear; baggage, luggage, paraphernalia, accouterments, things, goods, effects, movables, excess baggage, encumbrances; equipage, tackle, harness, rigging, apparatus, appurtenances,

impel, v. 1. urge or drive forward, press or urge on, exhort, impress; induce, persuade, prevail upon, insist upon, railroad, ramrod; constrain, oblige, necessitate, require, demand, force, make, exact, leave no option or choice; apply pressure, Inf pressure or high-pressure, Inf. lean on, Inf. squeeze, Inf. put the screws on or to, Inf. twist [s.o.'s] arm; draft, conscript, commandeer. 2. move, actuate, set in motion, get going; propel, push, shove, thrust, nudge; spur, prod, prick, goad, poke; lash, whip,

impending, adj. 1. imminent, about to happen, at hand, near or close at hand, near, close; coming, upcoming, forthcoming, to come, approaching, nearing; in store, in the wind, in the air, Inf. in the cards, Inf. on the books; in view, in prospect, in the offing, on the horizon.
2. threatening, menacing, lowering, looming, lurking; brewing, gathering, collecting,

impenetrable, adj. 1. impervious, imperviable, impassable, unpassable, inaccessible, unaccessible, jungly, jungled, overgrown; trackless, pathless, wayless, untrodden, Obs. invious.
2. proof, resistant, tight, snug, compact, hermetic, hermetically sealed; closed, shut, sealed, locked; solid, hard, rock-hard, adamantine; impermeable, unporous, nonporous, watertight, waterproof; punctureproof, imperforable, unperforable, imperforate, imperforated, unpierceable, unpierced, holeproof.