One having a word to both sides? (5)
I believe the answer is:
space
'one having a word to both sides?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'one' is the wordplay.
I cannot quite see how this works, but
'one' could be 'ace' (ace has a value of one in some card games) and 'ace' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for space that I've seen before include "Blank" , "Interstellar vacuum" , "Room; gap" , "Emptiness" , "Room for capes" .)