It is the hypothetical source of/evidence for its existence is provided by: Sanskrit antara- "interior;" Greek en "in," eis "into," endon "within;" Latin in "in, into," intro "inward," intra "inside, within;" Old Irish in, Welsh yn, Old Church Slavonic on-, Old English in "in, into," inne "within, inside."
late 14c., "guardian, custodian," from Old French tuteor "guardian, private teacher" (13c., Modern French tuteur), from Latin tutorem (nominative tutor) "guardian, watcher," from tutus, variant past participle of tueri "watch over, look at," a word of uncertain origin. De Vaan suggests the sense evolution is from "to protect," and suggests connection with Sanskrit tavas- "strong, powerful," Greek sōs "safe, safe and sound, healthy," from a root meaning "to be strong." Specific sense of "senior boy appointed to help a junior in his studies" is recorded from 1680s.
1776, "to tutor," from Latin intuit-, past participle stem of intueri "look at, consider," from in- "at, on" (from PIE root *en "in") + tueri "to look at, watch over" (see tutor (n.)). Meaning "to perceive directly without reasoning, know by immediate perception" is from 1840 (De Quincey), in this sense perhaps a back-formation from intuition. Related: Intuited; intuiting.
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Definitions of intuition from WordNet
instinctive knowing (without the use of rational processes);