Drew aka Drewbacca perfectly exemplifies this
definition:
His hairline resembles a staircase, now this wasn't done on purpose hence the "Fucked Up Hairline"
Visual Evidence:
Exhibit A:
http://farm4.static.flickr.com/3485/3183251697_f95103f461.jpg
Exhibit B:
http://farm4.static.flickr.com/3128/3178603647_11c3f91e80.jpg