Young lad acquires sunburn studying flora (6)
I believe the answer is:
botany
'studying flora' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'young lad acquires sunburn' is the wordplay.
'young lad' becomes 'boy' (lad can mean informally mean a boy).
'acquires' means one lot of letters goes inside another.
'sunburn' becomes 'tan' (synonyms).
'boy' enclosing 'tan' is 'BOTANY'.
Can you help me to learn more?
(Other definitions for botany that I've seen before include "nature study" , "the name of a bay" , "The scientific study of plants" , "Unlucky, doomed" , "Science of plants" .)