1
general::
unimportant
not important:
• The exact details are unimportant. • Girls' education was seen as unimportant.
of no/little importance
not important, or not very important. These phrases sound a little more formal than unimportant:
• If you're capable of doing the job, your age is of no importance. • It's of little importance whether or not this story is true.
minor
small and not very likely to have an important effect - used especially about changes, problems, injuries, damage, or differences:
• I've made a few minor changes. • The driver suffered minor injuries. • These are just minor problems.
trivial
very unimportant and not worth worrying about or spending time on:
• They had a disagreement about some trivial matter. • She tends to get upset about trivial things.
insignificant
very small and unimportant, especially when compared to other things:
• Her own problems seemed insignficant. • The amount of carbon they produce is relatively insignificant.
negligible
extremely small and not important - used especially about effects, amounts, differences, or risks:
• So far, the program has had a negligible effect. • The difference in price is negligible.
secondary
not as important as something else:
• These issues are of secondary importance. • For many women, a career is secondary to being mother.
Longman-Thesaurus