(slang) Alternative form of 彼氏 (kareshi, “boyfriend”)

everyone, one and all

nail biting

(of pets, animals, etc...) play biting

Same as above.

to chew, to digest / to fully appreciate, to fully understand

(literally) To bite one's own navel / (idiomatic) To be deeply regretful about something

lurker (in an online community) (abbr. ROM, ロム)

Alternative form of リードオンリーメモリ

The hiragana syllable す (su). Its equivalent in katakana is ス (su). It is the thirteenth syllable in the gojūon order; its position is さ行う段 (sa-gyō u-dan, “row sa, section u”).