Description

When the first choice font-family is unavailable font-size-adjust allows the browser to preserver the aspect value in the next available font by resizing the font to the size of the first preference.
The 'aspect value' is the font-size divided by x-height (height of a lowercase 'x')

Example

 p{
  font-family:verdana, sans-serif; 
  font-size-adjust:0.58;
}

Values
number representing the aspect value of the prefered font
Default value
none
Introduced in CSS version
3
Applies to elements
All
Inherited
Yes
Browser Support
BrowsersIEFirefoxSafariOperaChrome
Versionsnone3nonenonenone
Belongs to:

See the full list CSS properties and browser support: CSS Properties