the origin of "zilch" is obscure but is popularly traced to the 1930s american college slang, where "joe zilch" was used as a generic name for an insignificant or nonexistent person. this fictional name evolved into a slang term meaning "zero" or "nothing." its adoption into broader english was solidified in the mid-20th century, particularly in informal contexts, to emphatically denote a complete absence or lack of something.

this is a simplex word. it is a slang term of unknown origin, though often associated with a fictional character name used in the 1930s.