资料来源 : pyDict

在那以前,到那时为止

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Theretofore \There`to*fore"\, adv.
   Up to that time; before then; -- correlative with heretofore.

资料来源 : WordNet®

theretofore
     adv : up to that time; "they had not done any work theretofore"