noun Date: before 12th century the quality or state of being fast: as, the quality or state of being fixed, the quality or state of being swift, colorfast quality, resistance (as of an organism) to the action of a usually toxic substance, 2. a fortified or secure place, a remote and secluded place
FASTNESS
Meaning of FASTNESS in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012