coG a cog in the machine wheel

Achilles heel Where's the beef? Z-list a cog in the machine wheel a fat lot of good a one-horse town a poor relation a white elephant against ain't shit at a disadvantage backseat be like a spare prick ata wedding be no good to man or beast be of no account

الأهمية والدلالة المنفعة والميزة والامتياز