Wrong highlighting if name begins with "def"

[smithtim]

Description

Names that begin with def are highlighted differently than those which don't.

Steps to Reproduce

(+ defx fooy)

Expected behavior:

defx and fooy are the same color.

Actual behavior:

defx and fooy are different colors.

Versions

Atom : 1.58.0
Electron: 9.4.4
Chrome : 83.0.4103.122
Node : 12.14.1

macOS Big Sur 11.4