adverb
since a little while ago; for a while now
Indicates that a state or action has been continuing from a short time ago up to the present. Often used in formal or written contexts.
先ほど来、雨が降り続いている。
It has been raining since a little while ago.
先ほど来、電話が鳴りっぱなしだ。
The phone has been ringing non-stop for a while now.
Compound of 先ほど (sakihodo, 'a little while ago') + 来 (rai, 'since'). The 来 here is a Sino-Japanese suffix indicating 'since' or 'from'.