A mob, wanting book, showing cultivation (6)
I believe the answer is:
arable
'a mob wanting book showing cultivation' is the definition.
I can't tell whether this defines the answer.
'a mob wanting book' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'book' could be 'b' (abbreviation for book) and 'b' is found in the answer.
The remaining letters 'rale' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for arable that I've seen before include "Of land, fit to be cultivated" , "Such land is fit for tillage" , "may be ploughed through" , "Of land, fit for growing crops" , "(Of land) able to be cultivated" .)