When I run
1147 root 20 0 1227548 34604 5784 S 1,7 0,9 1:10.88 dockerd
dockerd is common Linux daemon, nothing more than that. You should disable it the way suitable for your OS, depending on system services manager used.
Here are some examples (docker service name may vary system to system). First command stops the service, second disables its launch on system start.
For systemd driven OS (e.g. Ubuntu 16.04, RHEL/CentOS 7, Arch Linux), that will be:
sudo systemctl stop docker sudo systemctl disable docker
For relatively old Ubuntu (before 15.10), using Upstart service manager:
sudo service docker stop sudo sh -c 'echo manual > /etc/init/docker.override'
For older CentOS6 and some others:
sudo service dockerd stop sudo chkconfig dockerd off
You should look for instructions on how to disable service for specific OS you're interested in