The Collaborative International Dictionary
Ganch \Ganch\, v. t. [Cf. F. ganche, n., also Sp. & Pg. gancho hook, It. gancio.] To drop from a high place upon sharp stakes or hooks, as the Turks dropped malefactors, by way of punishment.
Ganching, which is to let fall from on high upon hooks,
and there to hang until they die.
Douglas Harper's Etymology Dictionary
"to impale on hooks or pointed stakes as a means of capital punishment," 1610s, from French *ganchor, from Italian *ganciare, from gancio "hook," from Turkish kanca "hook, barb, grapnel." Related: Ganched; ganching. Also, as a noun, the name of the punishment or the thing used in it, 1620s.
vb. To drop from a high place upon sharp stakes or hooks as a punishment.