Both used to describe starting pitchers:
cuSP: A SP that's not there JUST YET, but right on the verge of a breakout season (i.e; Max Scherzer, Brian Matusz)
gaSP: I can't decide if this would describe a de la Rosa/Nolasco hit-or-miss type, or maybe a truly shocking pitching performance either way.
liSP: A rather effeminate starter.
Ha! These are good. Not sure about the last one, but definitely like the first two. Especially the first one. I could see actually using that one.