Shoot yak by Siberian border (5)
I believe the answer is:
stalk
'shoot' is the definition.
(thesaurus)
'yak by siberian border' is the wordplay.
'yak' becomes 'talk' (I've seen this in another clue).
'by' means one lot of letters go next to another.
'siberian border' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'talk' after 's' is 'STALK'.
Can you help me to learn more?
(Other definitions for stalk that I've seen before include "Follow prey stealthily" , "Shadow" , "Stem; pursue stealthily" , "Stem of plant" , "Stem; follow" .)