Getting low score on it is no great shakes (7,5)
I believe the answer is:
richter scale
'getting' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for richter scale that I've seen before include "Used to measure earthquake magnitude" , "Measure of earthquake strength" , "Measure of energy released by earthquakes" , "On which earthquakes are measured" , "On which an earthquake is measured" .)