the first council of Nicaea, the first general council of the Church, held in 325 ad to settle the Arian controversy
2.
the second council of Nicaea, the seventh general council of the Church, held in 787 ad to settle the question of images
Nicene Council in American English
either of two church councils that met in Nicaea in a.d. 325 and a.d. 787; esp., the first of these, that condemned Arianism and adopted the Nicene Creed