Light breakfast? It's of no great importance (5,3)
I believe the answer is:
small fry
This could be a double definition.
'light breakfast?' is the first definition.
The answer and definition can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'of no great importance' is the second definition.
The definition suggests a singular noun which matches the answer.
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for small fry that I've seen before include "Little fish or folk" , "Unimportant people like tiny fish" , "Insignificant people" , "Young ones in school" , "Not the full English breakfast" .)