Late, understand? Heard some water (4,3)
I believe the answer is:
dead sea
'water' is the definition.
(I know that Dead Sea is a water)
'late understand? heard' is the wordplay.
'late' becomes 'dead' (similar in meaning).
'understand?' becomes 'see' ('see' can be a synonym of 'understand').
'heard' indicates a 'sounds like' (homophone) clue.
'see' is a homophone of 'sea'.
'dead'+'sea'='DEAD SEA'
'some' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for dead sea that I've seen before include "Lake of Jordan/Israel" , "River Jordan flows into this" , "large salt lake" , "'Body of water, sounds like it's passed on (4,3)'" , "Inland salt lake in the Jordan valley of Israel" .)