What is rising and falling like waves; resembling wave form or motion; undulatory; rolling; wavy; as, an undulating medium; undulating ground. -- Un"du*la`ting*ly. adv called?

undulating — Rising and falling like waves; resembling wave form or motion; undulatory; rolling; wavy; as, an undulating medium; undulating ground. -- Un"du*la`ting*ly. adv. (Webster's 1913.)

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