What flows when measuring unusually dry places? (9)
I believe the answer is:
clepsydra
'what flows when measuring' is the definition.
I can't judge whether this defines the answer.
'unusually dry places?' is the wordplay.
'unusually' is an anagram indicator.
'dry'+'places'='dryplaces'
'dryplaces' with letters rearranged gives 'CLEPSYDRA'.
Can you help me to learn more?
(Other definitions for clepsydra that I've seen before include "Old timekeeper needing water" , "Ancient water clock" , "Water-clock" , "Old device with leaking water" , "old time technology" .)