Roughly jolt someone, initially start to elbow (6)
I believe the answer is:
jostle
'elbow' is the definition.
(I've seen this in another clue)
'roughly jolt someone initially start' is the wordplay.
'roughly' indicates anagramming the letters.
'initially' indicates taking the first letters.
'start' becomes 'e' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The first letter of 'someone' is 's'.
'jolt'+'s'='jolts'
'jolts' with letters rearranged gives 'jostl'.
'jostl'+'e'='JOSTLE'
'to' is the link.
Can you help me to learn more?
(Other definitions for jostle that I've seen before include "press" , "Push or bump roughly against someone" , "jockey" , "Knock against" , "Barge" .)