1So as to complete a circle or (with reference to the turning of a wheel, especially the wheel of fortune) a full rotation; (hence) so as to return to a starting point or complete a cycle. Especially in "to come full circle".
In earlier examples after Shakespeare's use.
2rare As or in the form of a full circle or disc.
Of a garment: forming a complete circle when spread out, and hanging in generous, full folds when worn.
Early 17th century; earliest use found in William Shakespeare (1564–1616), playwright and poet. From full + circle.