also: はなクソ
noun
booger; snot; nasal mucus
Casual, somewhat childish word for dried or wet nasal mucus. 鼻くそ is the most common written form.
子供が鼻くそをほじっている。
The child is picking his nose.
ティッシュで鼻くそを拭いた。
I wiped the snot with a tissue.
Mixed katakana spelling; adds emphasis or a casual, jocular tone.
Uncommon kanji spelling using 屎; rarely encountered.
鼻水 is the general word for runny nasal mucus, while 鼻くそ refers specifically to dried or semi-dried boogers.
Compound of 鼻 (nose) and くそ (excrement, waste). The second element is a common colloquial suffix for bodily waste products.