Introduction of short corner — one showing disdain (7)
I believe the answer is:
scorner
'one showing disdain' is the definition.
The definition suggests a singular noun which matches the answer.
'introduction of short corner' is the wordplay.
'introduction of' says to take the initial letters.
The first letter of 'short' is 's'.
's'+'corner'='SCORNER'
Can you help me to learn more?
(Other definitions for scorner that I've seen before include "I despise" , "One mocks" , "He's not taken advantage of" .)