Use Appearance font
To choose the dock text style from a list of presets, rather than manually choosing a font, size and style, check this box.
Font
To change the font used to draw the names of dock items, select a font from this popup menu.
Size
To change the size of the font used to draw the names of dock items, select a size from this popup menu.
Style
To change the style of the font used to draw the names of dock items, set the options in this popup menu.