obedient and dutious
obeisance and submission
objectionable and inexpedient
obligation and dependence
obliquity and hypocrisy
oblivious and insensible
obloquy and detraction [obloquy = abusive language]
obnoxious and odious
obscure and enigmatical
obsequies and panegyrics [obsequies = funeral rite] [panegyrics = elaborate praise]