Certain pseudoscience, for short (3)
I believe the answer is:
esp
(Other definitions for esp that I've seen before include "Second sight (abbr)" , "Initially, clairvoyance or telepathy" , "Apparent power to perceive things that others can't, in short" , "Extrasensory perception (abbrev.)" , "Apparent power to perceive things that others can't, initially" .)