Kerbside coin-swallower? (5)
I believe the answer is:
meter
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for meter that I've seen before include "Apparatus for measuring" , "Instrument for measuring quantity" , "Poe sometimes used this" , "Device for measuring and recording" , "Measuring device as for electricity usage (5)" .)