3.6.1 Removing labels and titles
Having set labels and titles, they may be removed thus:
set xlabel '' set ylabel '' set title ''
These are two other ways of removing the title from a plot:
set notitle unset title
The unset command may be followed by almost any word that can follow the set command, such as xlabel or title, to return that setting to its default configuration. The reset command restores all configurable parameters to their default states.