What is to cause to move backward and forward, or up and down, in undulations or waves; to cause to vibrate. Breath vocalized, that is, vibrated and undulated. Holder called?

undulate — To cause to move backward and forward, or up and down, in undulations or waves; to cause to vibrate. Breath vocalized, that is, vibrated and undulated. Holder. (Webster's 1913.)

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