adverb, adverb taking the 'to' particle, taru-adjective
in detail; minutely; at great length
Literary adverb used to describe explaining, recounting, or describing something exhaustively and in fine detail. Often used with verbs like 述べる, 説明する, or 語る.
彼は自分の体験を縷々と語った。
He recounted his experience in great detail.
報告書には問題点が縷々述べられている。
The report describes the problems minutely.
taru-adjective, adverb taking the 'to' particle
unceasing; continuous; unbroken
Literary use describing something that continues without interruption, such as a flow of words, rain, or a line of thought. Often appears as 縷々として.
雨が縷々として降り続いた。
The rain continued unceasingly.
彼の話は縷々として尽きることがなかった。
His talk went on unbrokenly without end.
The kanji 縷 means 'thread' or 'detailed', and the repetition 縷々 literally suggests 'thread after thread', metaphorically extending to 'in fine detail' or 'continuously'. The reading るる is the on'yomi.