If you say that habits or attitudes die hard, you mean that they take a very long time to disappear or change, so that it may not be possible to get rid of them completely.
Old habits die hard.
Such prejudices die hard.
See full dictionary entry for die
die hard in British English
to cease to exist after resistance or a struggle
old habits die hard
See full dictionary entry for die
die-hard in British English
noun
1.
a person who resists change or who holds onto an untenable position or outdated attitude
2. (modifier)
obstinately resistant to change
Derived forms
die-hardism (ˈdie-ˌhardism)
noun
die hard in American English
to cling to life, a cause, etc.; resist to the last
See full dictionary entry for die
die-hard in American English
(ˈdaɪˌhɑrd) or ˈdieˌhard (ˈdaɪˌhɑrd)
adjective
1.
stubbornly resistant to change or unwaveringly loyal even in spite of inevitable defeat, failure, etc.
a die-hard conservative, a die-hard fan of the losers
noun
2.
a person who displays such resistance or loyalty
Examples of 'die hard' in a sentence
die hard
Old habits die hard it seems.
Times, Sunday Times (2014)
Old habits die hard and I still stand on the right, not the left.
Times, Sunday Times (2016)
And not just the die-hard fans.
Times, Sunday Times (2010)
Comic fun for die-hard romantics.
The Sun (2006)
This warring buddy movie is probably only for die-hard fans of the cheery Chan.
Times, Sunday Times (2010)
Great news for die-hard fans.
The Sun (2009)
His die-hard fans have naturally accused his many Chinese critics of having a collective sense of humour failure.
Times, Sunday Times (2015)
But is it only die-hard fans who should consider buying, or do you have a sporting chance of making a profit?
Times, Sunday Times (2007)
(noun)
Definition
a person who resists change
Fanatical diehards are determined on derailing the peace process.
Synonyms
reactionary
Critics viewed him as a reactionary, even a monarchist.
fanatic
I am not a religious fanatic but I am a Christian.
zealot
He was forceful but by no means a zealot.
intransigent
stick-in-the-mud (informal)
a stick-in-the-mud who prefers the old, tried and tested methods
old fogey
ultraconservative
(modifier)
Even their die-hard fans can't pretend this was a good game.
Synonyms
reactionary
uncompromising
inflexible
intransigent
immovable
unreconstructed mainly US)
dyed-in-the-wool
ultraconservative
Additional synonyms
in the sense of fanatic
Definition
a person devoted to a particular hobby or pastime
I am not a religious fanatic but I am a Christian.
Synonyms
extremist,
activist,
militant,
addict,
enthusiast,
buff (informal),
visionary,
devotee,
bigot,
zealot,
energumen (archaic)
in the sense of stick-in-the-mud
Definition
a person who is unwilling to try anything new or do anything exciting
a stick-in-the-mud who prefers the old, tried and tested methods