An upper semicontinuous function whose restrictions to all Complex lines are subharmonic (where defined). These functions were introduced by P. Lelong and Oka in the early 1940s. Examples of such a function are the logarithms of moduli of holomorphic functions.
Range, R. M. and Anderson, R. W. ``Hans-Joachim Bremmermann, 1926-1996.'' Not. Amer. Math. Soc. 43, 972-976, 1996.