Pole on board involving prime minister in salutation (7)
I believe the answer is:
topmast
'pole on board' is the definition.
'topmast' can be an answer for 'pole' (topmast is a kind of pole). I'm unsure of the 'on board' bit.
'prime minister in salutation' is the wordplay.
'prime minister' becomes 'PM' (abbreviation).
'in' is an insertion indicator.
'salutation' becomes 'toast' (as in toasting someone with a drink).
'pm' inserted within 'toast' is 'TOPMAST'.
'involving' is the link.
Can you help me to learn more?
(Other definitions for topmast that I've seen before include "High part of sailing ship" , "Most apt (anag) - feature of a square-rigged ship" , "Sail-supporting section of a ship" , "Part of square-rigged ship" , "post on board" .)