Irascible stepmother strangely embarrassed? (5-8)
I believe the answer is:
short-tempered
'irascible' is the definition.
('short-tempered' can be a synonym of 'irascible')
'stepmother strangely embarrassed?' is the wordplay.
'strangely' indicates an anagram.
'embarrassed?' becomes 'red' (I've seen this before).
'stepmother' is an anagram of 'shorttempe'.
'shorttempe'+'red'='SHORT-TEMPERED'
(Other definitions for short-tempered that I've seen before include "Tending to anger quickly" , "Impatient" , "Irascible" , "Easily moved to anger" , "Testy" .)