Eccentric – Lengthen and refers to movement down towards the earth

(Pronounced ek-sen-trik)

To remember what eccentric means use the following mnemonic:

The eccentric professor just seemed to keep lengthening the equation on the blackboard.

And to remember it's down:

Relate the first letter of eccentric to:

E= Look down to Earth

E= Down

In Summary

Eccentric = Lengthen

Eccentric = Down

Eccentric would be a lengthening of a muscle and is usually associated with a movement downwards towards earth. 

An example of an eccentric contraction would be moving a dumbbell in a bicep curl back down towards the earth. Down being the memorable word.