Noun

(en noun)

A strong fortress that sits high above a city.

(sometimes, figurative) A stronghold or fortified place.

* 1836 , Alexander Slidell Mackenzie, The American in England (page 269)

Intrenched within the citadel of our apartment, and cheered by the comfortings of a coal fire, we passed the day in letter-writing, conversation, or gazing from the sheltered security of our windows upon the agitated sea

Noun

A secure or fortified place; a stronghold, a fortress

* {{quote-book

, year=1917 , year_published=1917 , edition= , editor= , author= , title= , chapter= citation , genre= , publisher=archive.org , isbn= , page= , passage=The incubators are built in remote fastnesses , where there is little or no likelihood of their being discovered by other tribes. }}

* 1919 ,

*:When she came to know writers it was like adventuring upon a stage which till then she had known only from the other side of the footlights. She saw them dramatically, and really seemed herself to live a larger life because she entertained them and visited them in their fastnesses .

The state of being fast.

# firmness, security

# rapidity, swiftness

The ability of a dye to withstand fading