compromise; concession; mutual accommodation
Refers to the act of meeting halfway or making mutual concessions, often in negotiations or relationships. Similar to 歩み寄り, but 歩み合い emphasizes the reciprocal nature of the compromise.
See also: 歩み寄り (あゆみより)
Without compromise from both sides, they probably won't reach an agreement.
Mutual accommodation is the secret to a lasting marriage.
Compound of 歩み (ayumi, 'walking; step') + 合い (ai, 'mutual; together'), literally 'walking together' or 'mutual stepping', referring to the process of meeting halfway.