Hardship is a related term of unhappiness.
As nouns the difference between hardship and unhappiness
is that hardship is (countable or uncountable) difficulty or trouble; hard times while unhappiness is the feeling of not being happy.
hardship
English
Noun
(
en noun)
(countable or uncountable) Difficulty or trouble; hard times.
- He has survived periods of financial hardship before.
unhappiness
English
Noun
The feeling of not being happy