noun Date: 1865 a usually small white mushroom ( Agaricus bisporus syn. A. brunnescens ) in which the pileus has not yet expanded
BUTTON MUSHROOM
Meaning of BUTTON MUSHROOM in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012