These words describe specific types of rapid, energetic motion of people, animals and sometimes inanimate objects. Skip and bound both emphasize a series of motions. To skip is to move in a sprightly, nimble fashion by stepping, jumping lightly and sliding on each foot in turn. It suggests lightheartedness and is commonly done by children or some young animals: to skip down the street to the sweet shop; goats skipping across the pasture. Skip is used also as a transitive verb to describe light, bouncing motions, especially across a surface: to skip a flat stone on the surface of the water.

Bound describes a more energetic motion than skip and involves longer and more rapid strides. Bound suggests high spirits and excitement: boys bounding down the beach after a ball; to bound across the room to answer the telephone. Bound may also imply fear or urgency: As we came near the scrub, a startled wallaby bounded across the road.

Leap and spring are closely related in meaning and are more precise than bound in that both involve rising and projecting oneself suddenly and vigorously upwards from the ground or other supporting surface and then darting forwards: to leap over a gate; to spring out of bed. Usually, spring indicates a more vigorous and catapulting motion than leap . Spring is used also in describing the sudden elastic or recoiling action of certain devices.

• The jaws of the trap sprang shut; The screen door sprang shut after the children rushed out to play.

Hop is to move in short, often jerky leaps as does a bird, frog or rabbit. Hopping lacks the grace and speed of skipping or bounding , or the energy of leaping and springing . Of human beings, hop suggests limping or jumping repeatedly on one foot as children do in certain games or in excitement.