With which, by means of which, wherewith.

By means of or by the agency of which; from which (as a source of information); according to which, in the matter of which, etc.

= wherethrough, adv.

With ellipsis of antecedent, or as nominal relative involving antecedent (cf. what, pron. III.): That, or something, with which; the means by…

In instrumental and allied senses: By means of which; whereby.

With that, or with which; therewith, wherewith: = withal, adv. 2. Obsolete.

In reference to agency or instrumentality (through, prep. 12): By means of which, whereby, wherewith. Now rare or Obsolete.

By means of which, with which, whereby, wherewith (of, prep. VI.). Obsolete or rare(archaic) except with full, etc. (= of which).

= therewith, adv. 2 3.

Followed by an infinitive: In what way; by what means. how to do = the way in which one should (or may) do; also elliptical, as how to, and often…

= wherewith, adv. 2. archaic.

= wherewith, adv. 4. Obsolete or rare (archaic).