Entry 1 sense Webster, 1913 Naturism /nāʹchər-ĭz-əm/ · Na·tur·ism · IPA /ˈneɪ.t͡ʃəɹˌɪz.əm/ 01 n. The belief or doctrine that attributes everything to nature as a sanative agent. 1. The belief or doctrine that attributes everything to nature as a sanative agent.(Med.)