Diminutive of Theodora or Edward, from Greek 'gift of God' or Old English 'wealthy guardian.'
Teddi is a feminine adaptation of Teddy, itself a diminutive of two entirely distinct given names: Theodore, from the Greek Theodoros meaning 'gift of God,' and Edward, from the Old English Eadweard meaning 'wealthy guardian.' The Teddy nickname became famous in the early 20th century through Theodore Roosevelt, and the 'teddy bear' — named after a political cartoon depicting Roosevelt's refusal to shoot a bear on a hunting trip — enshrined a warmth and cuddliness in the sound that no subsequent bearer can entirely escape.
The 'i' spelling feminizes and softens it further, moving toward the affectionate and playful. Teddi has been used sparingly but consistently as a feminine name through the latter 20th century, carried most recently into public visibility by Teddi Mellencamp, daughter of rock musician John Mellencamp and a cast member on The Real Housewives of Beverly Hills in the late 2010s. The name sits comfortably beside other 'vintage-nickname-as-given-name' choices like Billie, Frankie, and Lottie — names that feel both retro and unconventional, implying a certain ease with eccentricity. Teddi has the advantage of being immediately pronounceable and warm in feel while remaining genuinely uncommon, making it a name that feels familiar on first hearing but rarely shared on the playground.