Figure, name unknown, spread around river (7)
I believe the answer is:
numeral
'figure' is the definition.
(a numeral is a figure representing a number)
'name unknown spread around river' is the wordplay.
I cannot quite see how this works, but
'name' could be 'al' and 'al' is found within the answer.
'river' could be 'r' (abbreviation for river) and 'r' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for numeral that I've seen before include "Figure representing a value" , "1, 2, 3, say" , "Symbol for number" , "Figure or symbol like '1', for example" , "Affable and sociable" .)