  In this paper, we provide a new characterization of uniformly recurrent words
with finite defect based on a relation between the palindromic and factor
complexity. Furthermore, we introduce a class of morphisms P_ret closed under
composition and we show that a uniformly recurrent word with finite defect is
an image of a rich (also called full) word under a morphism of class P_ret.
This class is closely related to the well-known class P defined by Hof, Knill,
and Simon; every morphism from P_ret is conjugate to a morphism of class P.
