Barnet Hospital welcoming US university's key specialist (9)
I believe the answer is:
locksmith
'key specialist' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'barnet hospital welcoming us university's' is the wordplay.
'barnet' becomes 'locks' (both can mean hair).
'hospital' becomes 'H' (abbreviation for hospital on maps).
'welcoming' indicates putting letters inside (in sense of 'inviting in').
'us university' becomes 'MIT' (Massachusetts Institute of Technology).
'locks'+'h'='locksh'
'locksh' placed around 'mit' is 'LOCKSMITH'.
Can you help me to learn more?
(Other definitions for locksmith that I've seen before include "Maker of security devices" , "Security expert" , "Yale scholar" , "Security device maker" , "opener" .)