a real or imagined cause for complaint or protest

complaint, gripe

(an instance of) serious suffering; difficult conditions

personal burden

severity

severity

a very small difference or distinction

fine point

(of an instrument or process) giving exact measurements or results; accuracy

accuracy

an unpleasant situation from which escape seems difficult

difficult situation

severity

severity

the quality of being severe

asperity

a narrow passage of water connecting two seas; trouble; difficulty

crisis, difficulty