What is the root word of suspension

To find the root word of suspension you need to find the root word of its present verb form; suspend.

Breaking down suspend gives you sus-pend

Pend comes from the Latin word pendere

Pendere means: to having caused something to be hung; to hang down.

the state of a substance when its particles are mixed with but undissolved in a fluid or solidb: a substance in this state-see oral suspension or a system consisting of a solid dispersed in a solid, liquid, or gas usually in particles of larger than colloidal size.