Other forms: creeping, crept, creeps, creeped
To creep is to move slowly and quietly so as not to be noticed. Creep downstairs, creep up on somebody, creeping along the wall.
The past tense is crept. It also describes anything moving in slowly and unwelcome: costs crept up, doubt crept in, mission creep. Give somebody the creeps means to make them uneasy in a way they cannot quite name, and a creep is a person who does that — unpleasant and slightly frightening. Note creepy, the adjective, and that plants creep too, which is where creeper comes from.
1verbcreepTo move slowly and quietly so as not to be noticed.
“He crept out at about four in the morning.”
2verbincreaseTo increase or spread slowly and unwelcomely.
“The costs crept up about five per cent a year.”
3noununpleasantAn unpleasant person who makes others uneasy.
“Everybody in the building thought he was a creep.”
Too few real examples of this word to estimate which sense is commonest.
creep is a slow quiet movement.
Old English creopan comes from a Germanic root meaning to twist or wind. The same root gives cripple, and the idea behind all of them is a body bent low rather than upright.
Proto-Indo-European
*grewbʰ- — to turn, wind
Proto-Germanic
*kreupaną — to twist, creep
Proto-West Germanic
*kreupan
Old English
crēopan — to creep, crawl
Middle English
crepen
English, today
creep
From Middle English crepen, from Old English crēopan (“to creep, crawl”), from Proto-West Germanic kreupan, from Proto-Germanic kreupaną (“to twist, creep”), from Proto-Indo-European grewbʰ- (“to turn, wind”). 2 Cognate with West Frisian krûpe (“to creep, crawl”), gmw-cfr kruffe (“to creep, crawl”), Dutch kruipen (“to creep, crawl”), Low German krepen, krupen (“to creep, crawl”), Danish krybe (“to creep”), Faroese krúpa (“to creep”), Icelandic krjúpa (“to kneel down, to genuflect, to get down on one's knees”), Norwegian Bokmål krype (“to creep”), Norwegian Nynorsk krjupa, krjupe, krypa, krype (“to creep, crawl”), Swedish krypa (“to creep, crawl”).
Etymology from Wiktionary, CC BY-SA