Measurer of current force maintained by a sea of Frenchmen? (7)
I believe the answer is:
ammeter
'measurer of current' is the definition.
(I've seen this before)
'force maintained by a sea of frenchmen?' is the wordplay.
'force' becomes 'met' (I've seen this in other clues).
'maintained by' is an insertion indicator (maintain can mean to keep hold of).
'a sea of frenchmen?' becomes 'amer' (I can't justify this - if you can you should give a lot more credence to this answer).
'met' placed inside 'amer' is 'AMMETER'.
Can you help me to learn more?
(Other definitions for ammeter that I've seen before include "Device measuring electric current" , "Device that measures the flow of electrical current" , "Current-measuring instrument" , "Instrument that measures electric current." , "Current-measurer" .)