Confronted odd prof earlier who's kind of humourless (7)
I believe the answer is:
pofaced
'kind of humourless' is the definition.
I can't judge whether this definition defines the answer.
'confronted odd prof earlier' is the wordplay.
'confronted' becomes 'faced' ('face' can be a synonym of 'confront').
'odd' indicates alternate letters.
'earlier' says to put letters next to each other.
The alternating letters of 'prof' are 'po'.
'faced' after 'po' is 'POFACED'.
'who's' is the link.
Can you help me to learn more?
(Another definition for pofaced that I've seen is " visibly disapproving".)