Medic about right, with one attempt to determine source of giddiness (7)
I believe the answer is:
vertigo
'giddiness' is the definition.
(thesaurus)
'medic about right with one attempt' is the wordplay.
'medic about' becomes 've' (I can't explain this - if you can you should believe this answer much more).
'right' becomes 'rt'.
'with' means one lot of letters go next to another.
'one' becomes 'i' (Roman numeral).
'attempt' becomes 'go' (go is a kind of attempt).
've'+'rt'+'i'+'go'='VERTIGO'
'to determine source of' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for vertigo that I've seen before include "Sensitivity to heights" , "Sensation of dizziness brought on by heights" , "Dizziness due to disorder in sense of balance" , "that makes it hard to stand" , "Trouble with heights" .)