Fight to keep intruders out? (5)
I believe the answer is:
fence
This clue might be a double definition.
'fight' is the first definition.
(fencing is a kind of fighting)
'keep intruders out?' is the second definition.
'fence' can be an answer for 'keep' (thesaurus). I'm unsure of the 'intruders out?' bit.
'to' is the link.
Can you help me to learn more?
(Other definitions for fence that I've seen before include "Stolen goods dealer" , "feature in horse-racing?" , "Barrier; receiver" , "Shield" , "Bound over this" .)