Hum \Hum\, v. t.

1. To sing with shut mouth; to murmur without articulation; to mumble; as, to hum a tune.

2. To express satisfaction with by humming.

3. To flatter by approving; to cajole; to impose on; to humbug. [Colloq. & Low]

Source: Webster's Revised Unabridged Dictionary (1913)
 

Hum \Hum\, n.

1. A low monotonous noise, as of bees in flight, of a swiftly revolving top, of a wheel, or the like; a drone; a buzz.

The shard-borne beetle with his drowsy hums. --Shak.

2. Any inarticulate and buzzing sound; as:
   (a) The confused noise of a crowd or of machinery, etc., heard at a distance; as, the hum of industry.

But 'midst the crowd, the hum, the shock of men. --Byron.
   (b) A buzz or murmur, as of approbation. --Macaulay.

3. An imposition or hoax.

4. [Cf. Hem, interj.]

An inarticulate nasal sound or murmur, like h'm, uttered by a speaker in pause from embarrassment, affectation, etc.

THese shrugs, these hums and ha's. --Shak.

5. [Perh. so called because strongly intoxicating.]

A kind of strong drink formerly used. [Obs.]

--Beau. & Fl.

Venous hum. See under Venous.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Hum \Hum\, v. i. [imp. & p. p. Hummed; p. pr. & vb. n. Humming.]

[Of imitative origin; cf. G. hummen, D. hommelen. [root]15.]

1. To make a low, prolonged sound, like that of a bee in flight; to drone; to murmur; to buzz; as, a top hums. --P. Fletcher.

Still humming on, their drowsy course they keep. --Pope.

2. To make a nasal sound, like that of the letter m prolonged, without opening the mouth, or articulating; to mumble in monotonous undertone; to drone.

The cloudy messenger turns me his back, And hums. --Shak.

3. [Cf. Hum, interj.]

To make an inarticulate sound, like h'm, through the nose in the process of speaking, from embarrassment or a affectation; to hem.

4. To express satisfaction by a humming noise.

Here the spectators hummed. --Trial of the Regicides.

Note: Formerly the habit of audiences was to express gratification by humming and displeasure by hissing.

5. To have the sensation of a humming noise; as, my head hums, -- a pathological condition.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Hum \Hum\, interj. [Cf. Hem, interj.]

Ahem; hem; an inarticulate sound uttered in a pause of speech implying doubt and deliberation. --Pope.

Source: Webster's Revised Unabridged Dictionary (1913)