Stimulating
Part of speech: adjective
Definition: In a manner that stimulates.
Part of speech: verb
Definition: To encourage into action.
Example sentence: 'Candida' was difficult: stimulating but very wordy.
Invigorating
Part of speech: adjective
Definition: Giving strength, energy and vitality.
Part of speech: verb
Definition: To impart vigor, strength, or vitality to.
Example sentence: The soul, cramped among the petty vexations of Earth, needs to keep its windows constantly open to the invigorating air of large and free ideas: and what thought is so grand as that of an ever-present God, in whom all that is vital in humanity breathes and grows?