expression, noun, adverb
since then; ever since; from that time
Refers to a continuous state or repeated action starting from a past event. Often used at the beginning of a sentence or clause.
彼は去年引っ越して、それ以来一度も会っていない。
He moved away last year, and I haven't seen him once since then.
それ以来、毎朝ジョギングを続けている。
Ever since then, I've kept up my morning jogging.