compound noun from verb stems (行き帰り)

A compound noun formed by joining two verb stems (renyōkei): 行き帰り ('going-and-returning'), 出入り ('entering-and-leaving'), 売り買い ('selling-and-buying'), 上がり下がり ('rising-and-falling'), 乗り降り ('getting on and off'), 読み書き ('reading-and-writing'), 置き去り ('leaving behind' — 置く 'put' + 去る 'leave'). Often denotes paired or contrasting actions as an ongoing pattern, but also forms single result-nouns where the two stems compose into one meaning.