"guardianship," c. 1600, from -age + Latin tutela "a watching, keeping, safeguard, protection," from variant past participle stem of tueri "watch over" (see tutor (n.)). Meaning "instruction" first appeared 1857.
word-forming element in nouns of act, process, function, condition, from Old French and French -age, from Late Latin -aticum "belonging to, related to," originally neuter adjectival suffix, from PIE *-at- (source of Latin -atus, past participle suffix of verbs of the first conjugation) + *-(i)ko-, secondary suffix forming adjectives (see -ic).
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.
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Harper, D. (n.d.). Etymology of tutelage. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/tutelage