This is the 3420th most frequent Polish word.
włosów
"Hair" (genitive plural form).
Here, 'włosów' refers to the individual strands of hair collectively, indicating quantity.
Mam dużo włosów.
I have a lot of hair.
In this sentence, 'włosów' is in the genitive plural form, representing hair in general as an object of the action.
Zapomniałem o umyciu włosów.
I forgot about washing my hair.
Here, 'włosów' is used in the genitive plural form to describe possession of the color by the hair.