After today I may no longer have a gall bladder, but I'll always have gall.
gall - to have sufficient arrogance to do something.
gall 1 (gôl)
1. See bile.
a. Bitterness of feeling; rancor.
b. Something bitter to endure: the gall of defeat.
3. Outrageous insolence; effrontery.
[Middle English, from Old English gealla, galla; see ghel-2 in Indo-European roots.]
. . .
"bile," O.E. galla (Anglian), gealla (W. Saxon) "gall, bile," from P.Gmc. *gallon- (cf. O.N. gall, O.S., O.H.G. galla, Ger. Galle), from PIE root *ghel- "gold, yellow, yellowish-green" (see Chloe). Informal sense of "impudence, boldness" first recorded American English 1882; but meaning "embittered spirit, rancor" is from c.1200, from the medieval theory of humors. Gall bladder recorded from 1670s.
"sore spot on a horse," O.E. gealla "painful swelling," from L. galla "gall, lump on plant," originally "oak apple," of uncertain origin. Perhaps from or influenced by gall (1) on notion of "poison-sore." Ger. galle, Du. gal also are from Latin.
"to make sore by chafing," mid-15c., from gall (n.2). Earlier "to have sores, be sore" (early 14c.). Figurative sense of "harass, irritate" is from 1570s. Related: Galled; galling.