The # symbol has a proper technical name.
What is it?

The octothorpe.. Coined at Bell Labs in the 1960s. 'Octo' for the eight points; 'thorpe' — possibly a joke referencing athlete Jim Thorpe.

Question

Accepted Answer

The octothorpe. — Coined at Bell Labs in the 1960s. 'Octo' for the eight points; 'thorpe' — possibly a joke referencing athlete Jim Thorpe.