adverb
Rare literary adverb meaning 'for some time' or 'for a while', typically referring to a period leading up to the present. Not used in everyday conversation.
過般来、この問題について考えてきた。
I have been thinking about this problem for some time.
Compound of 過般 (kahan, 'recently; the other day') and 来 (rai, 'since; for the past'). The exact historical derivation is uncertain, but the word is a literary coinage.