'Threaten' definitions:

Definition of 'threaten'

verb

Pose a threat to; present a danger to; "The pollution is endangering the crops" [syn: endanger, jeopardize, jeopardise, menace, threaten, imperil, peril]

verb

To utter intentions of injury or punishment against:"He threatened me when I tried to call the police"

verb

To be a menacing indication of something:"The clouds threaten rain"; "Danger threatens"

From: GCIDE

Threaten \Threat"en\, v. i. To use threats, or menaces; also, to have a threatening appearance. [1913 Webster]
Though the seas threaten, they are merciful. --Shak. [1913 Webster]

From: GCIDE

Threaten \Threat"en\, v. t. [imp. & p. p. Threatened; p. pr. & vb. n. Threatening.] [OE. [thorn]retenen. See Threat, v. t.]
1. To utter threats against; to menace; to inspire with apprehension; to alarm, or attempt to alarm, as with the promise of something evil or disagreeable; to warn. [1913 Webster]
Let us straitly threaten them, that they speak henceforth to no man in this name. --Acts iv. 17. [1913 Webster]
2. To exhibit the appearance of (something evil or unpleasant) as approaching; to indicate as impending; to announce the conditional infliction of; as, to threaten war; to threaten death. --Milton. [1913 Webster]
The skies look grimly And threaten present blusters. --Shak. [1913 Webster]
Syn: To menace.
Usage: Threaten, Menace. Threaten is Anglo-Saxon, and menace is Latin. As often happens, the former is the more familiar term; the latter is more employed in formal style. We are threatened with a drought; the country is menaced with war. [1913 Webster]
By turns put on the suppliant and the lord: Threatened this moment, and the next implored. --Prior. [1913 Webster]
Of the sharp ax Regardless, that o'er his devoted head Hangs menacing. --Somerville. [1913 Webster]