The story
First attested in 1718, “untrustful, suspicious”, either from leer (“sideward look”) + -y, lear (“learning, knowledge”) + -y. More at leer, lear.
Etymology from Wiktionary, CC BY-SA 4.0.
leery
Today it means: Cautious, suspicious, wary, hesitant, or nervous about something; having reservations or concerns. Full definition →