face veil vs head covering

face veil and head covering both are nouns.

Word	Noun	Adjective	Verb	Adverb
face veil	Yes	No	No	No
head covering	Yes	No	No	No

As nouns, head covering is a hypernym of face veil; that is, head covering is a word with a broader meaning than face veil:

face veil: a piece of more-or-less transparent material that covers the face
head covering: a garment that covers the head and face

Other hypernyms of face veil include veil.

face veil (noun)	head covering (noun)
a piece of more-or-less transparent material that covers the face	a garment that covers the head and face