Tear into two very fit guards (5)
I believe the answer is:
halve
'tear' is the definition.
(thesaurus)
'very fit guards' is the wordplay.
'very' becomes 'v' (abbreviation).
'fit' becomes 'hale' (both can mean healthy).
'guards' indicates putting letters inside.
'v' placed into 'hale' is 'HALVE'.
'into two' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for halve that I've seen before include "Divide into two equal parts" , "split with another" , "Bisect" , "Cut into two equal portions" , "Divide into two equal pieces" .)