Delichon is a small genus of passerine birds that belongs to the swallow family and contains four species called house martins.
The name of the genus, "Delichon", is an anagram of the Ancient Greek term chelidon meaning swallow.

1/  Asian house martin (Nhạn hông trắng Á châu, Delichon dasypus)
dasypus is from Greek meaning "rough-legged".

2/ Nepal house martin (Nhạn hông trắng Nêpan, Delichon nipalense)
nipalense refers to Nepal, where the type specimen was obtained.

3/ Western house martin (Nhạn hông trắng Xibêri, Delichon urbicum), sometimes called the common house martin, northern house martin or, particularly in Europe, just house martin
The species name urbicum (urbica until 2004, due to a misunderstanding of Latin grammar) means "of the town" in Latin.