Two people, one face (4)
I believe the answer is:
dial
'face' is the definition.
(face of a clock)
'two people one' is the wordplay.
I cannot really understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
The remaining letters 'dal' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dial that I've seen before include "Coil of yarn" , "Face of a timepiece" , "Meter face" , "Indicator" , "Face with numbers" .)