I'm an odd sort of shape (7)
I believe the answer is:
diamond
'shape' is the definition.
(I've seen this before)
'i'm an odd sort' is the wordplay.
'sort' indicates anagramming the letters.
'im'+'an'+'odd'='imanodd'
'imanodd' anagrammed gives 'DIAMOND'.
'of' is the link.
(Other definitions for diamond that I've seen before include "(Usually colourless) gemstone - card" , "60th anniversary" , "Suit-baseball field - gem" , "A suit; a gem" , "Gem stone" .)