Require large English hypodermic (6)
I believe the answer is:
needle
'hypodermic' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'require large english' is the wordplay.
'require' becomes 'need' (synonyms).
'large' becomes 'L' (eg in clothes sizes).
'english' becomes 'E' (abbreviation as in OED).
'need'+'l'+'e'='NEEDLE'
Can you help me to learn more?
(Other definitions for needle that I've seen before include "Moveable bar in a compass" , "be irritating ?" , "counter" , "Injection" , "Movable bar in a compass" .)