Graduate isn't worried about old support (7)
I believe the answer is:
bastion
'support' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'graduate isn't worried about old' is the wordplay.
'graduate' becomes 'BA' (someone with a Bachelor of Arts degree).
'worried' is an anagram indicator (worry can mean to interfere with or disturb).
'about' indicates putting letters inside.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'isnt' with letters rearranged gives 'stin'.
'stin' enclosing 'o' is 'stion'.
'ba'+'stion'='BASTION'
Can you help me to learn more?
(Other definitions for bastion that I've seen before include "Stronghold, fortification" , "fortress" , "Obtains (anag.)" , "part of stronghold" , "A projecting fortification to increase angle of fire" .)