This is the 13464th most frequent German word.
besseres
"Better" (comparative form of "gut," used to indicate improvement or superiority).
In this sentence, 'besseres' is used as an adjective in the comparative degree, modifying 'nichts' (nothing)
Ich habe nichts Besseres zu tun.
I have nothing better to do.
Here, 'besseres' acts as an adjective in the comparative degree, describing 'Beispiel' (example).
Kannst du kein besseres Beispiel bringen?
Can you provide no better example?
In this instance, 'besseres' is a comparative adjective describing 'Leben' (life).