Q:

Why is the `nm` utility named as such?

The nm the utility to list symbols in a binary doesn't include in its documentation any explanation or clue of how it got to be named nm.
I imagine some of the long experienced UNIX developers can shed some light.
Why is the nm utility named as such?

A:

It's an abbreviation for "names" or "name list".

Nm prints the name list (symbol table) of each object file in the argument list.

(V7 Unix manual, 1979)

A:

Looking at http://pubs.opengroup.org/onlinepubs/9699919799/utilities/nm.html it looks like it is an abbreviation for "NaMe list".

