whistleblower (n.)

"tubular musical instrument sounded by blowing," Old English hwistle (see whistle (v.)). Meaning "sound formed by pursing the lips and blowing" is from mid-15c. To wet one's whistle "take a drink" (late 14c.) originally may have referred to pipes, or be an allusion to the throat as a sort of pipe. Phrase clean as a whistle is recorded from 1878. Railroad whistle-stop (at which trains stop only if the engineer hears a signal from the station) is recorded from 1934.

"move air, produce a current of air," Middle English blouen, from Old English blawan "to blow (of the wind, bellows, etc.), breathe, make an air current; kindle; inflate; sound" a wind instrument (class VII strong verb; past tense bleow, past participle blawen), from Proto-Germanic *blæ-anan (source of Old High German blaen, German blähen), from PIE root *bhle- "to blow."

The transitive sense of "carry by a wind or current of air" is from c. 1300; that of "fill with air, inflate" is from late 14c. Of noses, from 1530s; of electrical fuses, from 1902. The meaning "to squander" (money) is from 1874; that of "lose or bungle" (an opportunity, etc.) is by 1943. The sense of "depart (some place) suddenly" is from 1902.

As a colloquial imprecation by 1781, associated with sailors (as in Popeye's "well, blow me down!"); it has past participle blowed.

To blow (a candle, etc.) out "extinguish by a current of air" is from late 14c. To blow over "pass" is from 1610s, originally of storms. To blow hot and cold "vacillate" is from 1570s. To blow off steam (1837) is a figurative use from steam engines releasing pressure. Slang blow (someone or something) off "dismiss, ignore" is by 1986. To blow (someone's) mind was in use by 1967; there is a song title "Blow Your Mind" released in a 1965 Mirawood recording by a group called The Gas Company.

 For the sexual sense, see blow-job.