1. In sports (particularly soccer/football), a playing area that is smaller than regulation size
The training session was held on a diminished field to improve player concentration.
O treino foi realizado em um campo diminuído para melhorar a concentração dos jogadores.
2. In general usage, any reduced or limited area of activity or influence
The company operates in a diminished field after losing market share.
A empresa opera em um campo diminuído após perder participação de mercado.