We don't have synonyms for field coils yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are field coil and field goals.
(n) :
(electrical engineering) An electromagnet, consisting of a coil of wire through which a current flows, used to generate a magnetic field in an electromagnetic machine, typically a rotating machine such as a motor or generator.
(n) :
(electrical engineering) An electromagnet, consisting of a coil of wire through which a current flows, used to generate a magnetic field in an electromagnetic machine, typically a rotating machine such as a motor or generator.