agnosticism UK /æɡˈnɒstɪsɪzəm/US /æɡˈnɑstɪsɪzəm/ noun4 •The view that absolute truth or ultimate certainty is unattainable, especially regarding knowledge not based on experience or perceivable phenomena. •The view that the existence of God or of all deities is unknown, unknowable, unproven, or unprovable. •Doubt, uncertainty, or scepticism regarding the existence of a god or gods.1956, January 31ˢᵗ: Alan Alexander Milne; quoted in: — 1956 •Doubt, uncertainty, or scepticism regarding any subject of dispute. formsagnosticisms