Synonyms for Electric chair:

n.

death row, crucifixion, form of capital punishment, capital punishment, death sentence, the chair, death warrant, toaster, execute, the death penalty, instrument of execution, roaster, behead. chair for executions (noun)
hot seat, death chair, the chair.
electric chair (noun)
death chair, chair, hot seat.
punishment device (noun)
rack, stake, rope, block, guillotine, noose, whipping post, ax, thumbscrew, prison, rawhide, pillory, strap, birch rod, switch, iron, rod, scaffold, gallows, bull whip, cowhide, gibbet, maiden, jail, stocks, cane, captivity, truncheon, torture chamber, lash, thong, solitary confinement, whip, gas chamber.

Other synonyms:

the death penalty, behead, death row, capital punishment, crucifixion. Other relevant words:
the chair, capital punishment, hot seat, chair, death chair.