Creates a new named font and returns its name. fontname specifies the name for the font; if it is omitted, then Tk generates a new name of the form fontx, where x is an integer. There may be any number of option-value pairs, which provide the desired attributes for the new named font. See FONT OPTIONS for a list of the possible attributes.
A common pattern is to create a new font based on an existing one. E.g., you can create a bold font that is exactly the same as TkTextFont, just being bold:
font create boldFont {*}[font configure TkTextFont] -weight boldIf you want to use the actual attributes that are obtained when the font is used on window's display, you can use font actual instead of font configure. Note: this will only work with Tcl 8.5 and higher due to the {*} word.