Young farm animal initially swimming lake during trial (9)
I believe the answer is:
shearling
'young farm animal' is the definition.
The definition suggests a singular noun which matches the answer.
'initially swimming lake during trial' is the wordplay.
'initially' says to take the initial letters.
'lake' becomes 'L' (geographical abbreviation).
'during' means one lot of letters goes inside another.
'trial' becomes 'hearing' (as in a court hearing).
The initial letter of 'swimming' is 's'.
'l' inserted into 'hearing' is 'hearling'.
's'+'hearling'='SHEARLING'
Can you help me to learn more?
(Another definition for shearling that I've seen is " it's been fleeced".)