NLP stands for Neuro-Linguistic Programming.

N = Neurology The mind and how we think
L = Linguistics How we use language and how it affects us
P = Programming How we sequence actions to achieve our goals

Here are some well-known definitions:

“NLP is an accelerated learning strategy for the detection and utilization of patterns in the world” (John Grinder)
“NLP is whatever works” (Robert Dilts)
“NLP is an attitude and a methodology that leaves behind a trail of techniques” (Richard Bandler)
“NLP is the study of the structure of subjective experience” (Robert Dilts)

And here’s my version:

“NLP is learning to read maps – your own and other people’s – and the art of changing those maps, playfully and lovingly, to create more choices and open new doors.”