Definition of mickles:
(adj) :
(archaic, now chiefly Scotland and Northern England, especially Northumbria) (Very) great or large.
(adv) :
(archaic, now chiefly Scotland) To a great extent.
(n) :
(archaic, chiefly Scotland) A great amount.
(n) :
(archaic, Scotland, originally erroneous) A small amount.
(n) :
(obsolete) Great or important people as a class.
(n) :
(obsolete) Greatness, largeness, stature.