Common words that rhyme with companion include opinion, union, occasion, affection, adoration, passion, adulation, inclination, appreciation, nation, condemnation, vacation, authorization, dispensation and confirmation.
With respect to your opinion, I must disagree.
The union discussed absenteeism during negotiations.
The wedding was a memorable occasion.
The company reported gross revenue of $1 million.
She showed her affection for him.
She practiced the ritual with great devotion.