\hbar is used a lot in physics. Once in a while, one also uses \lambdabar to mean \lambda/2\pi. It's Unicode description is 'LATIN SMALL LETTER LAMBDA WITH STROKE' (U+019B). I've been using this hack \def\lambdabar{\lambda\kern-1ex\raise0.65ex\hbox{-}} But it's not beautiful. Is there a better way to get a lambdabar into (or from) the math fonts? I tried \def\lambdabar {\Umathchar "0"0"00019B } by analogy with the definition of \hbar in luatex-math.tex, but it produces a blank space. There must be no entry for it in the regular (or Palatino) math fonts. For reference, the following thread had a discussion about \hbar http://www.ntg.nl/pipermail/ntg-context/2013/070810.html and \hbar works well (using MkIV 2014.02.14). -Sanjoy