Precision Approach Path Indicator - Used in avionics to guide planes to the runway using the approach path (Glide Path).
A series of 3 or 4 lights that change colour from white to red in accordance to the height of the aircraft.

Red over Red - Too low
Red over White - On the Glide path
White over White - Too high

The PAPI lights can be seen up to 5 miles in daylight and upto 20 miles at night.

Noun

1. A Spanish word (Central American) term that literally translates as 'father' into English. It is often used along with papa to refer to ones father.

2. A slang term that is similar in affect to Daddy in the phrase "Who's your Daddy?!" Often given by women to their boyfriends/husbands or to their sex partner. It is most often used during intercourse, but is also just used as a pet name. During intercourse it can be used to describe both pain or pleasure. For example "AI! Papi!" with emphasis on the Ai could be used when it is hurting, while "Ai papi!" or "Oh papi!" could indicate pleasure.

3. A title sometimes taken on by the leading members of a gang, similar to the Father of a Mafia.

A sexy latino or black male that has lotta personality & apariance. Mostly use in hispanics males.

Spanish- "Big daddy" - typically combined with "Aye" during sexual encounters with young latin ladies from south Texas if you're hitting the right spot

pet name for boyfriend

pet name used by a female for a male, mainly by carribbean peoples (puerto ricans, cubans, columbians, and floridians). can be used for friends/boyfriends/husbands/ or random people.

a lot of people assume it is only used for lovers, but it is used for anyone who is male.

Papi = Daddy

the name spanish people call EVERYONE.