Is calling the non-Muslim a "disbeliever" a derogatory term?

Does the Christian not consider the Muslim a disbeliever, for instance, because he does not believe in the Trinity, and that he will not be admitted to the Kingdom of God except through having faith in it? "Disbelief" is a term that means denial of the truth, and the truth for the Muslim is represented in Tawhīd (monotheism), and for the Christian it is the Trinity.