Feeling of dismay with smile after tea (7)
I believe the answer is:
chagrin
'feeling of dismay' is the definition.
'chagrin' can be an answer for 'dismay' (I've seen this in another clue). I'm not certain of the 'feeling of' bit.
'smile after tea' is the wordplay.
'smile' becomes 'grin' (grinning is a kind of smiling).
'after' says to put letters next to each other.
'tea' becomes 'cha' (cha is a type of tea).
'grin' put after 'cha' is 'CHAGRIN'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for chagrin that I've seen before include "Disappointment, exasperation" , "Strong feeling of embarrassment" , "Annoy" , "Feeling of annoyance and embarrassment" , "Emotion" .)