The answer
Metanoia is a Greek word (μετανοία) made of two parts: meta- (μετα) which means to change or to elevate, and nous (νους) which means the mind; thus, metanoia is the elevation of the mind or the repentance that is offered to God as a form of worshipping Him.
A metanoia can also be offered to one’s brethren or even prophets as a form of seeking forgiveness of a particular sin committed by an individual or a congregation. In this way, the faithful honor one another and show mutual respect for one another.
Metanoias are always accompanied by making the sign of the cross and a short prayer that will differ to suit the purpose of the metanoia. St. Isaac the Syrian enjoins us to offer metanoias constantly, finding sweetness in this constancy even after three days of kneeling on the ground, praying, without feeling weary, because of the sweetness and enjoyment that the faithful find in this practice.316
Fr. Tadros Yacoub Malaty
Notes
316 See A Monk of the Baramous Monastery (H. G. Bishop Macarius), An Introduction to Metanoias in Spiritual Direction (Arabic), fourth printing (2002): p. 42.