Webster's Revised Unabridged Dictionary · 1913

Roar

Roar , intransitive verb

[Old English roren, raren, Anglo-Saxon rārian; akin to German rohten, Old High German rērēn. r112.]

1.
To cry with a full, loud, continued sound.
(a)
To bellow, or utter a deep, loud cry, as a lion or other beast.
Roaring bulls he would him make to tame. — Spenser
(b)
To cry loudly, as in pain, distress, or anger.
Sole on the barren sands, the suffering chief Roared out for anguish, and indulged his grief. — Dryden
He scorned to roar under the impressions of a finite anger. — South
2.
To make a loud, confused sound, as winds, waves, passing vehicles, a crowd of persons when shouting together, or the like.
The brazen throat of war had ceased to roar. — Milton
How oft I crossed where carts and coaches roar. — Gay
3.
To be boisterous; to be disorderly.
It was a mad, roaring time, full of extravagance. — Bp. Burnet
4.
To laugh out loudly and continuously; as, the hearers roared at his jokes.
5.
To make a loud noise in breathing, as horses having a certain disease. See Roaring, 2.
Collocations (2)
Roaring boy , a roaring, noisy fellow; -- name given, at the latter end Queen Elizabeth's reign, to the riotous fellows who raised disturbances in the street. Two roaring boys of Rome, that made all split. — Beau. & Fl
Roaring forties (Nautical) , a sailor's name for the stormy tract of ocean between 40° and 50° north latitude.

Roar , transitive verb

To cry aloud; to proclaim loudly.
This last action will roar thy infamy. — Ford

Roar , noun

The sound of roaring.
(a)
The deep, loud cry of a wild beast; as, the roar of a lion.
(b)
The cry of one in pain, distress, anger, or the like.
(c)
A loud, continuous, and confused sound; as, the roar of a cannon, of the wind, or the waves; the roar of ocean.
Arm! arm! it is, it is the cannon's opening roar! — Byron
(d)
A boisterous outcry or shouting, as in mirth.
Pit, boxes, and galleries were in a constant roar of laughter. — Macaulay