<p><strong>Verb</strong></p><ul><li>(Used without object) To move slowly with the body close to the ground, as a reptile or an insect, or a person on hands and knees.</li><li>To approach slowly, imperceptibly, or stealthily (often followed by up): We crept up and peeked over the wall.</li><li>To move or advance slowly or gradually: The automobile crept up the hill.</li><li>To sneak up behind someone or without someone's knowledge (usually followed by up on): The prisoners crept up on the guard and knocked him out.</li><li>To enter or become evident inconspicuously, gradually, or insidiously (often followed by in or into): The writer's personal bias occasionally creeps into the account.</li><li>To move or behave timidly or servilely.</li><li>To grow along the ground, a wall, etc., as a plant.</li><li>To advance or develop gradually so as to infringe on or supplant something else.</li><li>Slang. To flirt with or make persistent sexual advances toward someone (often followed by on): He creeps on all the women he meets.</li><li>To cheat on one’s sexual partner: He caught his wife creepin' with the guy who lives next door.</li><li>Slang. To follow someone persistently or stealthily, as on a social media website (often followed by on): He spends a lot of time creeping on her Facebook profile.</li><li>Slang. To suddenly intrude into someone’s photograph as it is being taken: Who’s that creeping in the background of the picture?</li><li>To slip, slide, or shift gradually; become displaced.</li><li>(Of a metal object) To become deformed, as under continuous loads or at high temperatures.</li><li>Nautical. To grapple (usually followed by for): The ships crept for their anchor chains.</li></ul><p><strong>Noun</strong></p><ul><li>An act or instance of creeping: It seems as if time has slowed to a creep.</li><li>Slang. An obnoxious, disturbingly eccentric, deviant, or painfully introverted person.</li><li>Slang. An intelligence or counterintelligence agent; spy.</li><li>A gradual or inconspicuous increase, advance, change, or development: Avoid jargon creep in your writing.</li><li>Geology. The gradual movement downhill of loose soil, rock, gravel, etc.; solifluction.</li><li>The slow deformation of solid rock resulting from constant stress applied over long periods.</li><li>Mechanics. The gradual, permanent deformation of a body produced by a continued application of heat or stress.</li><li>A grappling iron; grapnel.</li><li>Firearms. The slack in a trigger mechanism before it releases the firing pin.</li><li>Creep feeder.</li><li>The creeps, Informal. A sensation of horror, fear, disgust, etc., suggestive of the feeling induced by something crawling over the skin: That horror movie gave me the creeps.</li></ul><p><strong>Verb Phrase</strong></p><ul><li>Informal. To cause to experience uneasiness or disgust: I was so creeped out that I had to sleep with the lights on. She’s been getting crank calls that are creeping her out.</li></ul>