Words that rhyme with stirn

What do these rhymes mean?

adjourn

close at the end of a session; "The court adjourned" break from a meeting or gathering; "We adjourned for lunch

concern

something that interests you because it is important or affects you

discern

detect with the senses; "The fleeing convicts were picked out of the darkness by the watchful prison guards

return

document giving the tax collector information about the taxpayer's tax liability

unconcern

the trait of remaining calm and seeming not to care; a casual lack of concern a feeling of lack of concern