(a plant with) an orange root, used as a vegetable

lure, inducement

something that produces an effect, that makes something happen

agent, originator

an organic chemical substance formed in plants and animals, able to cause chemical changes without being changed itself

something which incites activity

the state of being excited

enthusiasm; incitement

to encourage, urge a person, especially to do wrong

stimulus

the force with which a body moves

stimulus, force

a sudden desire to act without thought about the consequences; a short increase in strength, force

drive, resolve

that which incites or encourages a person

lure, inducement

influence(s) producing creative activity in literature, music, art etc; a person or thing that inspires

idea, stimulus

a cause or reason for doing something

reason, purpose

a drink etc that gives new energy, cheerfulness

stimulant

something that annoys

incitement, stimulus

the basic reasons (for a belief, decision, course of action etc)

logic for belief, action

a person's soul, mind; an invisible being, e.g. a ghost, fairy, elf etc; state of mind; the quality of having courage, determination

soul, attitude

one of a pair of sharp-toothed wheels on the heels of a rider's boots, used to make the horse go faster

incitement, stimulus

a drink (e.g. coffee, brandy), drug etc that increases bodily or mental activity; anything that encourages a person (e.g. praise, hope of gain)

substance that invigorates

something that encourages (a person to do something, an activity etc); something, e.g. light, heat, electricity that causes an animal or plant to do something

provocation