Charades, IV

I'm a word of one syllable. Look you for me Mid Niagara's roar; in the turbulent sea; Where the winds and the waters are wildest at play, And fling off their laughter in volumes of spray.

I'm a noun of five letters; but throw one aside— I'm a verb; with the noun I'm no longer allied. I'm a grave, solemn verb; nay, I truly might say, Those who follow my precept do nothing but pray.

But again; let two letters be dropped—there's a change; As a noun—and by no means a grave one—I range. Now I'm here; now I'm there; seen by night and by day, For in short, I'm a beam, or a flash, or a ray.

Thus a verb and two nouns packed together you see, In a word of one syllable.—What can it be?