whereby
adverb, conjunction uk/weəˈbaɪ/ us/werˈbaɪ/
C2 由此，从而；借以
by which way or method
They've set up a plan whereby you can spread the cost over a two-year period. 他们已经制订了这样一个计划，允许在一段时间内分期付款。
We need to devise some sort of system whereby people can liaise with each other. 我们需要设计一套办法，人们能够借以互相保持联络。
not standard在…的情况下;处于…的位置
in which, or with which
It's put me in a position whereby I can't afford to take a job. 这使我到了一种连工作也做不了的地步。