The katakana syllable スィ (si). Its equivalent in hiragana is すぃ (si).

Alternative form of スィー (sī, “see”) (name of the letter C, c)

drink

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

all you can drink

drinking party

(slang) communication between people drinking together

drunkard