The act of entering or delving into something — either physically stepping in or figuratively confronting/dealing with an issue in depth.
記者が現場に踏み込み、詳しい状況を報告した。
A reporter entered the scene and reported the detailed situation.
議論は踏み込み不足で結論が出なかった。
The discussion lacked depth and no conclusion was reached.
警察が夜間に踏み込み捜査を行った。
The police conducted a raid/entry search at night.
In architecture, 'fumikomi' can refer to a recessed or stepped area inside a room — a small alcove or lowered section (usage and exact sense vary by region/texts).
古い民家の踏み込みには季節の飾りが置かれていた。
Seasonal decorations were placed in the recessed area of the old folk house.