Noun

(en noun)

An imaginary rock or mineral of impenetrable hardness; a name given to the diamond and other substances of extreme hardness.

* {{quote-book

, year= 1582 , year_published= , author= , by= , title= The first booke of the Christian exercise, appertayning to resolution , url= http://books.google.com/books?id=gvbik25DcCgC&pg=PT144 , original= , chapter= 8 , section = , isbn= , edition= , publisher= G. Flinton , location= , editor= , volume= , page= , passage= This then is and alwayes hath ben the fashion of Worldlinges, & reprobate persons, to harden their hartes as an adamant stone, against anye thinge that shalbe tolde the for amendement of their lives, and for the savinge of their soules. }}

An embodiment of impregnable hardness.

* 1956 , , The City and the Stars , p 34

Unprotected matter, however adamant , would have been ground to dust ages ago.

A magnet; a lodestone.

* 1594–96 , :

You draw me, you hard-hearted adamant :

But yet you draw not iron, for all my heart

Is true as steel. Leave you your power to draw,

And I shall have no power to follow you.

Noun

(en noun)

The property of being persistent.

You've got to admire his persistence . He's asked her out every day for a month even though she keeps turning him down.

(computer science) Of data, continuing to exist after the execution of the program.

Once written to a disk file, the data has persistence : it will still be there tomorrow when we run the next program.

(meteorology) Continuation of the previous day's weather (particularly temperature and precipitation statistics).