What's the difference between theretofore and whereat?

Theretofore


Definition:

  • (adv.) Up to that time; before then; -- correlative with heretofore.

Example Sentences:

  • (1) Pseudomonas putrefaciens should theretofore be retained as a single species and characteristics for identifying the various groups within the species are listed.
  • (2) Generally speaking, the news media don't lament the theretofore bright futures of young men (or women) convicted of other violent crimes, such as the killing of girlfriends or executing down-on-their-luck job-hunters .

Whereat


Definition:

  • (adv.) At which; upon which; whereupon; -- used relatively.
  • (adv.) At what; -- used interrogatively; as, whereat are you offended?

Example Sentences:

  • (1) ), whereat measurements can be taken either using cylindrical graphitic walls or "no walls".