In short, disoriented sailor following new navigational aid (5,4)
I believe the answer is:
north star
'navigational aid' is the definition.
(I've seen this before)
'in short disoriented sailor following new' is the wordplay.
'in' is an insertion indicator.
'disoriented' indicates an anagram.
'sailor following' becomes 'tar' (I can't explain this - if you can you should give a lot more credence to this answer).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'short' is an anagram of '[short]'.
'[short]'+'tar'='orthstar'
'orthstar' enclosing 'n' is 'NORTH STAR'.
Can you help me to learn more?
(Other definitions for north star that I've seen before include "nickname of US State" , "guiding light" , "feature of Ursa Minor" , "Polaris" , "Navigational aid" .)