A martlet in English heraldry is a heraldic charge depicting a stylized bird similar to a house martin or swallow, with stylised feet. It should be distinguished from the merlette of French heraldry, which is a duck-like bird with a swan-neck and chopped-off beak and legs.
The word "martlet" is derived from the bird known as the martin, with the addition of the diminutive suffix "-let"; thus martlet means "little martin". The origin of the name martin is obscure, though it may refer to the festival Martinmas, which occurs around the same time martins begin their migration from Europe to Africa.
These heraldic birds are shown properly in English heraldry with two or three short tufts of feathers in place of legs and feet. Swifts, formerly known as martlets, have such small legs that anciently they were believed to have none at all.
In French heraldry the canette or anet is a small duck (French: canard), shown without feet. According to Théodore Veyrin-Forrerla canette représente la canne ou le canard; si elle est dépourvue du bec et des pattes, elle devient une merlette. ("The canette represents the duck or drake; if she is deprived of beak and feet she becomes a merlette"). In French un merle, from Latin merula, is a male blackbird, a member of the thrush family. A merlette in common parlance is a female blackbird, but in heraldic terminology is defined as une figure représentant une canette mornée ("a figure representing a little female duck 'blunted'"). Une cane is a female duck (male canard, "drake") and une canette, the diminutive form, is " a little female duck". The verb morner in ancient French means "to blunt", in heraldic terminology the verbal adjective morné(e) means: sans langue, sans dents, sans ongles et des oiseaux sans bec ni serres ("without tongue, without teeth, without nails and birds without beak or claws"). English heraldry uses the terms "armed" and "langued" for the teeth, claws and tongue of heraldic beasts, thus mornée might be translated as "dis-armed". Thus the English "martlet" is not the same heraldic creature as the French "merlette".