Word Study
wagtail
CIDE DICTIONARY
wagtail, n.
Any one of many species of Old World singing birds belonging to Motacilla and several allied genera of the family Motacillidæ . They have the habit of constantly jerking their long tails up and down, whence the name. [1913 Webster]
OXFORD DICTIONARY
wagtail, n. any small bird of the genus Motacilla with a long tail in frequent motion.
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