make-face-bold
make-face-bold is an interactive compiled Lisp function in `faces.el
'.
(make-face-bold FACE &optional FRAME NOERROR)
Make the font of FACE be bold, if possible.
FRAME nil or not specified means change face on all frames.
Argument NOERROR is ignored and retained for compatibility.
Use `set-face-attribute' for finer control of the font weight.