The Spanish live on water! (4)
I believe the answer is:
elbe
'water' is the definition.
Both the answer and definition are singular nouns.
Perhaps you can see a link between them that I can't see?
'the spanish live on' is the wordplay.
'the spanish' becomes 'el' ('the' in Spanish).
'live' becomes 'be' (synonyms).
'on' says to put letters next to each other.
'el'+'be'='ELBE'
Can you help me to learn more?
(Other definitions for elbe that I've seen before include "A major German river" , "European river" , "Flower" , "Dresden/Hamburg river" , "It flows through Germany" .)