whereby

where +‎ by

• enPR: wâr-bī', IPA^(key): /wɛə(ɹ)ˈbaɪ/

• Audio (US)

  (file)

• Rhymes: -aɪ

whereby (not comparable)

1. (interrogative, obsolete) By what, in which direction; how.

   Whereby goest thou?

2. By which.
   • c. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene i]:

     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.

   • 1990, Local management of schools, Kogan Page Ltd:

     Other heads saw devolution as a whole new way of life and adopted an approach whereby the power of devolution was used to enable the school to drive the curriculum.

3. (nonstandard) Where, wherein, in which.

Use of whereby as a formal equivalent of where is nonstandard and is avoided by careful speakers and writers, who use where or in which instead. The term typically fails readability and comprehension review so it is generally avoided in published works.