Start a command with a worse priority than the default

Answer

nice -n 10 gzip -9 archive.tar nice -n 10 make -j4 > build.log 2>&1 &

A positive nice value is added to the priority value, making it larger and therefore worse. Any user may raise it; only the superuser may set a negative one.

S&K 3e ch10 §10.2–10.3