Where does “cross-tail” come from?

cross-tail (English) comes from English cross-, from Irish cros-, from Irish cros, from Old Irish cros, from Latin crux, from Proto-Italic *kruks, from Proto-Indo-European sḱer- — to caw, crow.

cross-tail (English): A bar in a steam engine connecting the ends of the side rods or levers of a backaction or side-lever engine

Definitions

A bar in a steam engine connecting the ends of the side rods or levers of a backaction or side-lever engine

Ancestry of “cross-tail”, step by step

Step	Language	Word	Meaning
1	English	cross-	exchange; switch; across; Indicating...
2	Irish	cros-	cross-
3	Irish	cros	cross; crosspiece; trial, affliction
4	Old Irish	cros	cross
5	Latin	crux	wooden frame on which criminals were crucified,...
6	Proto-Italic	*kruks	—
7	Proto-Indo-European	sḱer-	to caw, crow

Every word from Proto-Indo-European sḱer- →Every word from Proto-Italic *kruks →Every word from Latin crux →