Scare - but Id be in familiar surroundings (10)
I believe the answer is:
intimidate
'scare' is the definition.
(intimidate can mean to scare)
'id be in familiar surroundings' is the wordplay.
'be in' indicates putting letters inside.
'familiar surroundings' becomes 'intimate' (I can't justify this - if you can you should believe this answer much more).
'id' placed inside 'intimate' is 'INTIMIDATE'.
'but' is the link.
Can you help me to learn more?
(Other definitions for intimidate that I've seen before include "Scare" , "Cow" , "Threaten" , "Frighten" , "Strike fear into" .)