1 [martinet]. Indiscriminately a swallow, swift or (house) martin. -
Cf. next
2) Her. A bird without legs or feet, used as a *charge; the *cadency of a fourth son. This notional bird is shown without feet or legs because the swift and swallow were thought never to perch as they supposedly lacked the feet to do so. -
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.