Transformer \Trans*form"er\, n.

Multiple transformer. (Elec.)
   (a) A transformer connected in multiple or in parallel with the primary circuit.
   (b) A transformer with more than one primary or more than one secondary coil.

Parallel transformer (Elec.), a transformer connected in parallel.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Transformer \Trans*form"er\, n. One who, or that which, transforms. Specif. (Elec.), an apparatus for producing from a given electrical current another current of different voltage.

Source: Webster's Revised Unabridged Dictionary (1913)