Breeches are an article of clothing covering the loins, worn as an undergarment; they are more fully blazoned a “pair of breeches”. They’re a period charge, found in the canting arms (Dutch broek) of van Abbenbroeke, c.1460 [GATD 35]. Breeches are affronty by default.
Also found in Society armory are “trews”, the outer garment worn between the waist and the knees: what in modern terms would be “trousers” or “pants”. Trews are period garments, but no examples of their use as an heraldic charge have been found in period. See also hose.
Frae Fitzalleyne bears: Gules, a pair of breeches ermine.
Jane Corwin bears as a badge: A pair of breeches argent.
Antonius Hasebroek bears as a badge: Per pale purpure and Or, a pair of trews potent.