Shopper is an agent, not a comparative. Many of the words ending in -er are comparative because they are based on a comparison like big, bigger, biggest, fast, faster, fastest. But when the word changes from an action to a person or noun then it is an agent like shopper, editor, creator, etc.
agent
a male shopper = koneh (×§×•× ×”) a female shopper = konah (×§×•× ×”)
"Litter" is a noun and a verb and, as such, does not have a comparative degree.
smoother is comparative of word smooth.
A comparative for the word ineffectual is more ineffectual.
Dative ; hot Comparative ; hotter Superlative ; hottest
comparative
Sharper is the comparative form of the word sharp.
comparative
comparative
What's the comparative and superlative of the word "exact"
The synonym for the word "comparative" is "relative" or "analogous."