Noun: Juice; Plural Noun: Juice
“Juice” (in the context of genitalia) refers to the fluid that is released from a woman’s vagina when aroused (or less commonly, during intercourse).
“Dude-bro, check that drippy-juicy puss’ down yonder!”
Discharged from a lady’s lady-parts, juice describes the (exaggerated) fluid that dribbles down a woman’s thighs when when she becomes aroused. It is used to convey extreme horniness. It is generally yellowish in color, and as a result it may be mistaken as urine. Some artists may choose to render vaginal juices as a translucent or white fluid, not dissimilar from a man’s cum.
Juice is not cum; it is pre-cum at best. Yes, this is an important detail.
Anime art tends to feature the juiciest content. Juice is seldom seen in 3D renders or western artwork. I think that it is equivalent to the “bloody nose” trope in anime. For those of you scratching your heads, it’s thing for anime characters to shoot blood out of their noses when they see someone exceptionally attractive — don’t ask me why, that’s just how it works. Anime artists like to convey emotion by metaphors and exaggeration, and a pair of sopping wet thighs are a widely accepted symbol for “horny”.
That, or not making it to the john on time.