Dirty blonde means you have dark blonde hair. It gets the word "dirty" because common dirt is brown and "dirty blonde" hair is hair that looks as if it is blonde mixed with brown, making the blonde darker. "browny" isn't a word, so you have to think of a synonym for brown, or something that is brown--like dirt. Plus, dirty blonde hair just sounds better than something like "Tree Bark Blonde" don't you think?
Patrisha calls herself "dirty blonde" when, in reality, her hair color is a light brown not a dark blonde color.
A gorgeous, unique, more seductive shade of blonde. Ranging from the color of honey to the shade of most beach sand. Generally makes a woman appear more mysterious and sexy since it is not as common/ordinary as brunette and not as fake looking as lighter blonde hair. (Also can be called "dark blonde")
"Actually, dirty blondes do it better."
"Forget about plain old blondes and brunettes, dirty blonde's where it's at."