After commencement of inflammation, Smith is worried about constrictions (6)
I believe the answer is:
isthmi
'constrictions' is the definition.
Although both the answer and definition are plural nouns, I cannot see how they can define each other.
'after commencement of inflammation smith is worried' is the wordplay.
'after' means one lot of letters go next to another.
'commencement of' indicates taking the first letters.
'is worried' indicates anagramming the letters.
The initial letter of 'inflammation' is 'i'.
'smith' is an anagram of 'sthmi'.
'i'+'sthmi' is 'ISTHMI'.
'about' is the link.
Can you help me to learn more?
(Other definitions for isthmi that I've seen before include "Necks of land" , "Geographical name for narrow strips of land which link two larger areas" .)