(ˈ) ̷ ̷| ̷ ̷ conjunction
Etymology: Middle English wherthrough, from where, wher where + through
1.
a. : through which : from one side to another of which
foliage wherethrough the sun shot sudden showers of light — Robert Nichols
b. : during which
seven long years of lack wherethrough he hath not ceased to seek for thee — Edwin Arnold
2. : because of which : on account of which
is in control of clocks, wherethrough it calls the tune — David Morton