That's surprising and it's sadly not something one could name (7)
I believe the answer is:
whatsit
'something one could name' is the definition.
(word used when the speaker can't remember a name)
'that's surprising and it's sadly' is the wordplay.
'that's surprising' becomes 'what' (what?!).
'and' is a charade indicator (letters next to each other).
'sadly' indicates an anagram.
'its' is an anagram of 'sit'.
'what'+'sit'='WHATSIT'
'not' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for whatsit that I've seen before include "Thingumajig" , "Thingummy" , "person not to be named" , "something indefinable" , "Something one can't recall" .)