Connection point Navy has left (3)
I believe the answer is:
tie
'connection' is the definition.
(tie is a kind of connection)
'point navy has left' is the wordplay.
'point' becomes 'tine' (I've seen this in another clue).
'navy' becomes 'N' (common abbreviation eg in RN Royal Navy).
'has left' indicates named letters should be taken away.
'tine' with 'n' removed is 'TIE'.
(Other definitions for tie that I've seen before include "Get even" , "Fasten; draw" , "Bond > girl wearing this? Unlikely" , "Almost level" , "Knot; achieve the same score" .)