If you mean from the Polar Experiment Network for Geophysical Upper-atmosphere Investigations (SAUS), the N is either 'network' or from 'INvestigations'.
It could stand for N/A -non aplickable
A letter in math can stand for any number
hen chicken penguin puffin
penguin stand for p for penguin E eat fish G for give eggs U for under the water I for in Antarctica and the 2 n for not a bird that flies
Live & Neutral
The Civil War doesn't stand for anything.
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern PEN---N. That is, seven letter words with 1st letter P and 2nd letter E and 3rd letter N and 7th letter N. In alphabetical order, they are: penguin pension
Nag
Robber Penguin Force
penguin secret agency
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern P---U-N. That is, seven letter words with 1st letter P and 5th letter U and 7th letter N. In alphabetical order, they are: penguin pinguin
where is the dangerous microphone in club penguin? The answer is in the forest