transitive verb

1. 1. to make threats against; express one's intention of hurting, punishing, etc.
   2. to express intention to inflict (punishment, reprisal, etc.)
2. 1. to indicate the likely occurrence of (something dangerous, unpleasant, etc.) clouds threatening snow
   2. to be a source of such danger, harm, etc. to an epidemic that threatens the city

Etymology: ME thretnen < OE threatnian

intransitive verb

1. to make threats
2. to be an indication or source of potential danger, harm, etc.