Facial guard — it is taken from guest (5)
I believe the answer is:
visor
'facial guard' is the definition.
'visor' can be an answer for 'guard' (a visor is a guard for one's eyes). I'm unsure of the 'facial' bit.
'it is taken from guest' is the wordplay.
'is taken from' indicates named letters should be taken away.
'guest' becomes 'visitor' (I've seen this before).
'visitor' with 'it' taken out is 'VISOR'.
Can you help me to learn more?
(Other definitions for visor that I've seen before include "Sunshade" , "Sunscreen" , "Means of saving face" , "Anti-glare flap over the windscreen" , "Face-armour" .)