ضيف

اـِسْمَاآءٌ مُتَضَايِفَةٌ ذ Correlative nouns; i. e. nouns significant of the existence of persons, or things, whereof the existence of one necessarily indicates the existence of another; as أَبٌ and اِبْنٌ [father and son]. (Er-Rághib, TA.)