noun
drinker; person who prefers alcohol over sweets
Often contrasted with 甘党 (sweet tooth). Describes someone who would rather have alcohol than sweets, not necessarily a heavy drinker.
See also: 甘党
私は甘いものよりお酒が好きで、完全に辛党です。
I prefer alcohol to sweets, so I'm definitely a drinker.
彼は辛党だから、デザートよりビールを選ぶ。
He's a drinker, so he'll choose beer over dessert.
noun
person who likes spicy food
Colloquial extension of the original meaning. Uses the kanji 辛 (spicy) literally, unlike the alcohol sense.
辛党の友達と激辛ラーメンを食べに行った。
I went to eat super-spicy ramen with a friend who loves spicy food.