The story
From neutral + -on; by surface analysis, neutr(o)- + -on. Coined by Scottish-Australian physicist William Sutherland in 1899 in a paper in the Philosophical Magazine. Subsequent usage was sporadic and theoretical, sometimes referring to neutrinos rather than neutrons, and the modern sense was reintroduced alongside proton by Ernest Rutherford in 1920.
Etymology from Wiktionary, CC BY-SA 4.0.