Strong drink consumed by son and daughter hastily (9)
I believe the answer is:
steadfast
'strong' is the definition.
(I've seen this before)
'drink consumed by son and daughter hastily' is the wordplay.
I cannot quite see how this works, but
'drink' could be 'tea' (tea is a drink) and 'tea' is found within the answer.
'son' could be 's' (genealogical abbreviation for son) and 's' is present in the answer.
'daughter' could be 'd' (genealogical abbreviation) and 'd' is located in the answer.
The remaining letters 'fast' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for steadfast that I've seen before include "Fixed, unyielding" , "stable" , "Firm and dependable" , "Dedicated" , "Resolutely firm" .)