whereby

adverb3

1. •
   By which.

   • Shylock: Nay, take my life and all; pardon not that: You take my house when you do take the prop That doth sustain my house; you take my life When you do take the means whereby I live. — 1596
2. •
   (nonstandard) Where, wherein, in which.
3. •
   (no longer used) By what, in which direction; how.

   • Whereby goest thou?