These words all mean to move furtively or stealthily, and all express an evident desire to stay hidden or unnoticed. Lurk can mean to lie hidden or to exist unnoticed or unsuspected: a snake lurking in the grass; What evil lurks in the hearts of men? But its most pertinent sense here is to move secretly or furtively, always with the implication of menace: assassins lurking among the crowd. The implied danger is often vague and ill-defined, which only increases the suggestion of menace: dark, shadowy figures lurking in alleyways.

Slink , creep and steal all mean to move quietly or furtively, but, whereas slink and creep often suggest fear as a motive for remaining hidden, steal may suggest other motives. Slink often points to a sly, guilty or abject attitude, and suggests a cowering posture and a fairly rapid gait: The beggar, refused a hand-out, slunk away into the shadows. Creep , in its basic sense, means to move with the body close to or touching the ground: Commandos creeping through the undergrowth. As here considered, creep often suggests timidity or fear as a cause of slow, very deliberate movement, regardless of posture: We crept up the staircase, our hearts pounding. But it can also mean any slow movement: The train fairly crept along. Steal emphasizes the secrecy of a mission: He stole over to his friend’s locker when his back was turned and dropped a frog in his shoe. Both steal and creep can be used figuratively.

• A note of pathos crept into her voice; For the first time a feeling of pity stole into his heart.

Skulk , more than slink , suggests guilt or shame as a motive for passing unnoticed: For months after his release from prison, he skulked around the house, afraid to show his face during the day. But it may also suggest sober caution and, in still other contexts, menace: to skulk past a gang of street-corner louts; a tough waterfront neighbourhood with clusters of figures skulking in front of every bar. Unlike slink or creep, skulk does not suggest any particular gait; it may imply the hunched-over posture of one wishing to remain undetected, but no mental picture is invariably associated with it. Sneak gives no clue at all either to posture or gait, thus emphasizing motive – the wish to remain unnoticed – to the exclusion of manner. Sneak can apply to trivial or innocent events as well as serious ones: to sneak into a circus tent; to sneak away from a party; to sneak into the kitchen for a snack. It suggests mischief or cowardliness more often than menace, and, unlike lurk , seldom or never suggests the threat of criminal acts.

Prowl means to roam about stealthily in search of prey or plunder: lions prowling for gazelles. When applied to people, prowl can suggest danger or may emphasize only the predatory instinct: would-be bashers prowling for victims; young men prowling the streets (or on the prowl) for girls. Prowl car is a colloquialism for a police patrol car, so called because unless on call, it typically moves slowly and in a more or less random manner, as an animal would while searching for prey. Thus prowl , alone of these words, may suggest a beneficial motive for stealth.