  Two link diagrams are link homotopic if one can be transformed into the other
by a sequence of Reidemeister moves and self crossing changes. Milnor
introduced invariants under link homotopy called $\bar{\mu}$. Nanophrases,
introduced by Turaev, generalize links. In this paper, we extend the notion of
link homotopy to nanophrases. We also generalize $\bar{\mu}$ to the set of
those nanophrases that correspond to virtual links.
