Home terms display a measurer (5)
I believe the answer is:
meter
'a measurer' is the definition.
(I've seen this in another clue)
'home terms display' is the wordplay.
'display' indicates a hidden word (I've seen 'displaying' mean this).
'METER' can be found hidden inside 'home terms'.
(Other definitions for meter that I've seen before include "Instrument for measuring quantity" , "Gauge" , "Measuring device, say for electricity usage" , "Device for measuring and recording" , "Device that measures, say, electricity usage" .)