adverb
in pieces; into many parts
Literary or classical adverb describing something being broken, scattered, or divided into many small pieces or fragments. Often used in poetic or dramatic contexts.
鏡が千々に砕け散った。
The mirror shattered into a thousand pieces.
彼の心は千々に乱れていた。
His heart was torn into a thousand pieces.
The exact derivation is uncertain. The kanji 千 means 'thousand', and the repetition suggests 'thousands', giving the sense of many pieces. The reading ちぢに is a classical Japanese form.