1570s, from tip (v.1); compare drowsy, flimsy, tricksy. Later associated with tipple. Tipsy-cake (1806) was stale cake saturated with wine or liquor.[tipsy etymology, tipsy origin, 英语词源]
1786, "characterized by tricks," from trick (n.) + -y (2). Meaning "deceptively difficult" is from 1868. Related: Trickily; trickiness. Earlier was tricksy (1590s).