petard n.

1896, "aggressive, exuberant, touchy," American English, with -y (2) + feist "small dog," earlier fice, fist (American English, 1805); short for fysting curre "stinking cur," attested from 1520s, with present participle of now-obsolete Middle English fysten, fisten "break wind" (mid-15c.), from Proto-Germanic *fistiz "a fart," said to be from PIE *pezd- (see fart), but there are difficulties.

The 1811 slang dictionary defines fice as "a small windy escape backwards, more obvious to the nose than ears; frequently by old ladies charged on their lap-dogs." Compare also Danish fise "to blow, to fart," and obsolete English aske-fise, "fire-tender," literally "ash-blower" (early 15c.), from an unrecorded Norse source, used in Middle English for a kind of bellows, but originally "a term of reproach among northern nations for an unwarlike fellow who stayed at home in the chimney corner" [OED].

1540s, "to raise, lift, elevate," especially with a rope or tackle, earlier hoise (c. 1500), from Middle English hysse (late 15c.), which probably is from Middle Dutch hyssen (Dutch hijsen) "to hoist," related to Low German hissen and Old Norse hissa upp "raise," Danish heise, Swedish hissa. A nautical word found in most European languages (French hisser, Italian issare, Spanish izar), but it is uncertain which coined it. Related: Hoisted; hoisting. In phrase hoist with one's own petard, it is the past participle.

For 'tis the sport, to have the engineer

Hoist with his own petar: and it shall go hard

But I will delve one yard below their mines,

And blow them at the moon: O 'tis most sweet,

When in one line two crafts directly meet.

["Hamlet," Act III, Scene iv]

Meaning "to lift and remove" was prevalent c. 1550-1750. As a noun, 1650s, "act of hoisting;" 1835, "that by which something is hoisted," from the verb.

"lice infestation," 1809, with -osis + Latin pediculus, diminutive of pedis "a louse," said in some sources to be akin to pedere "to break wind" (see petard) on notion of "foul-smelling insect" [Watkins]. But de Vaan traces it to a PIE *pesd- "annoying insect" and compares Avestan pazdu- "beetle, maggot." Pedicule "louse" is attested in Middle English (early 15c.).