Edible-nest swiftlet 
(Yến hông xám, Aerodramus fuciphagus), also known as the white-nest swiftlet

The edible-nest swiftlet (Aerodramus fuciphagus), also known as the white-nest swiftlet, is a small bird of the swift family which is found in Southeast Asia.

As the name apodiforme—meaning "footless" in Greek—suggests, the legs of hummingbirds, swifts and treeswifts (or 'crested' swifts) are rather small and offer limited functional uses.
The family name, Apodidae, is derived from the Greek ἄπους (ápous), meaning "footless", a reference to the small, weak legs of these most aerial of birds.

Aerodramus comes from two Ancient Greek words: aēr (ἀήρ), meaning "air," and dromos (δρόμος), meaning "path" or "runner". The name therefore translates to something like "air-path" or "air-runner," referring to swiftlets that navigate their environment through the air. 

The specific epithet fuciphaga combines the Ancient Greek φυκος/phukos meaning "seaweed" with -φαγος/-phagos meaning "-eating".