Oddly a hornet is not the same ...
I believe the answer is:
another
'not the same' is the definition.
(I've seen this before)
'oddly a hornet' is the wordplay.
'oddly' indicates anagramming the letters.
'a'+'hornet'='ahornet'
'ahornet' is an anagram of 'ANOTHER'.
'is' is the link.
(Other definitions for another that I've seen before include "encore?" , "Additional: alternative" , "On earth (anag.)" , "A different (thing)" , "A further (item)" .)