many such lists can be found online; here's one of them:

* imposing, 1 : impressive 2 : taking unwarranted advantage

* trip, 1 : step lightly 2 : stumble or cause to stumble

* overlook, 1 : observation point 2 : fail to see

* buckle, 1 : fasten together 2 : fall apart

* clip, 1: separate (cut) 2 : fasten

* oversight, 1 : supervision 2 : neglect

* qualified, 1 : competent 2 : limited

* sanction, 1 : approve 2 : disapprove

* temper, 1 : soften 2 : strengthen

* resign, 1 : give up, quit 2 : sign on again.

* left, 1: Gone 2: stayed behind

* let -- meaning (1) allow and (2) hinder or obstuct

* fast -- meaning (1) speedy and (2) standing still

* scan --1. to examine minutely. 2. to glance at hastily.

* chuffed, 1: pleased; satisfied 2 : displeased; annoyed

* tabled, 1: brought forward for discussion (UK) 2: laid aside (US)

* sententious, 1: Full of pithy expressions. 2: Full of pompous moralizing.

(not all of these are opposites, strictly speaking)