Of uncertain origin. Attempts have been made to derive it from various Germanic and Slavic roots. It was certainly in use in Poland in the 19th century, and is found in Polish folk tales as the name of a princess. The derivation may well be from the ethnic term Wend (see Wendell). The name was introduced to the English-speaking world by Ouida (Marie Louise de la Ramée), who used it for the heroine of her novel Wanda (1883).
Scottish and northern Irish: nickname for someone with long legs or some peculiarity of gait, from Old English sceanca ‘shin bone’, ‘leg’. This vocabulary word was preserved in Scotland, whereas in England it was replaced by Old Norse leggr.