A person who is regarded as underhanded and furtive and contemptible.

Roget 941: knave, rogue; Scapin^†, rascal; Lazarillo de Tormes; bad man etc. 949; blackguard etc. 949; barrater^†, barrator^†; shyster [U.S.].    traitor, betrayer, archtraitor^†, conspirator, Judas, Catiline; reptile, serpent, snake in the grass, wolf in sheep's clothing, sneak, Jerry Sneak, squealer [Slang], tell-tale, mischief-maker; trimmer, fence-sitter, renegade etc. (tergiversation) 607; truant, recreant; sycophant etc. (servility) 886.    ... show more

Roget 862: cowardice, pusillanimity; cowardliness etc. adj.; timidity, effeminacy.    poltroonery, baseness; dastardness^†, dastardy^†; abject fear, funk; Dutch courage; fear etc. 860; white feather, faint heart; cold feet [U.S.], yellow streak [Slang].    coward, poltroon, dastard, sneak, recreant; shy cock, dunghill cock; coistril^†, milksop, white liver, lily liver, nidget^†, one that cannot say 'boo' to a goose; slink; Bob Acres, Jerry Sneak.    alarmist, terrorist^†, pessimist; runagate etc. (fugitive) 623.    ... show more

Roget 949: bad man, wrongdoer, worker of iniquity; evildoer etc. 913; sinner; the wicked etc. 945; bad example.    villain, rascal, scoundrel, miscreant, budmash^†, caitiff^†; wretch, reptile, viper, serpent, cockatrice, basilisk, urchin; tiger^†, monster; devil etc. (demon) 980; devil incarnate; demon in human shape, Nana Sahib; hellhound, hellcat; rakehell^†.    bad woman, jade, Jezebel.    scamp, scapegrace, rip, runagate, ne'er-do-well, reprobate, scalawag, scallawag.    rou_e [Fr.], rake; Sadist; skeesicks [Slang], skeezix [U.S.]; limb; one who has sold himself to the devil, fallen angel, ame damnee [Fr.], vaurien^†, mauvais sujet [Fr.], loose fish, sad dog; rounder [Slang]; lost sheep, black sheep; castaway, recreant, defaulter; prodigal etc. 818.    rough, rowdy, hooligan, tough, ugly customer, mean mother [Coll.], ruffian, bully, meanie [Joc.]; Jonathan Wild; hangman.    incendiary, arsonist, fire bug [U.S.].    thief etc. 792; murderer, terrorist etc. 361.    [person who violates the criminal law] culprit, delinquent, crook, hoodlum, hood, criminal, thug, malefactor, offender, perpetrator, perp [Coll.]; disorderly person, misdemeanant [Law]; outlaw; scofflaw; vandal; felon, (convicted criminal); criminal; convict, prisoner, inmate, jail bird, ticket of leave man; multiple offender.    blackguard, polisson^†, loafer, sneak; rapscallion, rascallion^†; cullion^†, mean wretch, varlet, kern^†, ame-de-boue [Fr.], drole^†; cur, dog, hound^†, whelp^†, mongrel^†; lown^†, loon, runnion^†, outcast, vagabond; rogue etc. (knave) 941; ronian^†; scum of the earth, riffraff; Arcades ambo^†.    ... show more

Someone who prowls or sneaks about; usually with unlawful intentions.

synonyms: prowler, stalker.

Dutch: sluiper, duiker, geheimschrijver, gluiper, gluiperd, stiekemerd

Someone acting as an informer or decoy for the police.

synonyms: canary, fink, sneaker, snitch, snitcher, stool pigeon, stoolie, stoolpigeon.

To go stealthily or furtively:
— ..stead of sneaking around spying on the neighbor's house.

synonyms: creep, mouse, pussyfoot.

Roget 886: cringe, bow, stoop, kneel, bend the knee; fall on one's knees, prostrate oneself; worship etc. 990.    sneak, crawl, crouch, cower, sponge, truckle to, grovel, fawn, lick the feet of, kiss the hem of one's garment, kiss one's ass [Vulg.], suck up.    pay court to; feed on, fatten on, dance attendance on, pin oneself upon, hang on the sleeve of, avaler les couleuvres [Fr.], keep time to, fetch and carry, do the dirty work of.    go with the stream, worship the rising sun, hold with the hare and run with the hounds.    ... show more

Roget 940: be dishonest etc. adj.; play false; break one's word, break one's faith, break one's promise; jilt, betray, forswear; shuffle etc. (lie) 544; live by one's wits, sail near the wind.    disgrace oneself, dishonor oneself, demean oneself; derogate, stoop, grovel, sneak, lose caste; sell oneself, go over to the enemy; seal one's infamy.    ... show more

Roget 528: conceal, hide, secrete, put out of sight; lock up, seal up, bottle up.    encrypt, encode, cipher.    cover, screen, cloak, veil, shroud; cover up one's tracks; screen from sight, screen from observation; drawing the veil; draw the curtain, close the curtain; curtain, shade, eclipse, throw a view over; be cloud, be mask; mask, disguise; ensconce, muffle, smother; befog; whisper.    keep from; keep back, keep to oneself; keep snug, keep close, keep secret, keep dark; bury; sink, suppress; keep from, keep from out of view, keep from out of sight; keep in the shade, throw into the shade, throw into background; stifle, hush up, smother, withhold, reserve; fence with a question; ignore etc. 460.    keep a secret, keep one's own counsel; hold one's tongue etc. (silence) 585; make no sign, not let it go further; not breathe a word, not breathe a syllable about; not let the right hand know what the left is not let the right hand know what the left is doing; hide one's light under a bushel, bury one's talent in a napkin.    keep in the dark, leave in the dark, keep in the ignorance; blind, blind the eyes; blindfold, hoodwink, mystify; puzzle etc. (render uncertain) 475; bamboozle etc. (deceive) 545.    be concealed etc. v.; suffer an eclipse; retire from sight, couch; hide oneself; lie hid, lie in perdu [Fr.], lie in close; lie in ambush (ambush) 530; seclude oneself etc. 893; lurk, sneak, skulk, slink, prowl; steal into, steal out of, steal by, steal along; play at bopeep^†, play at hide and seek; hide in holes and corners; still hunt.    ... show more

Roget 862: quail etc. (fear) 860; be cowardly etc. adj., be a coward etc. n.; funk; cower, skulk, sneak; flinch, shy, fight shy, slink, turn tail; run away etc. (avoid) 623; show, the white feather.    ... show more

Dutch: treuzelen, trippelen, sluipen

Put, bring, or take in a secretive or furtive manner.

Make off with belongings of others.

synonyms: abstract, cabbage, filch, hook, lift, nobble, pilfer, pinch, purloin, snarf, swipe ... show more.

Dutch: verdonkeremanen, ontwenden, stelen, ontvreemden

Pass on stealthily.

synonym: slip.

Marked by quiet and caution and secrecy; taking pains to avoid being observed:
— A sneak attack.

synonyms: furtive, sneaky, stealthy, surreptitious.