Thesaurus

fastness

noun

Synonyms and Antonyms of FASTNESS

1
a high rate of movement or performance <the amazing fastness with which the boy took his shower had us wondering if he'd used any water>
2
a structure or place from which one can resist attack <the guerillas retreated to their network of hidden fastnesses deep within the mountains>

Browse

How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears