someone who visits stores in search of articles to buy
"The busy shopper hurried through the mall, carefully comparing prices on every item she picked up from a rack."
a commercial agent who shops at the competitor's store in order to compare their prices and merchandise with those of the store that employs her
"The buyer sent a shopper down to our rival's outlet last week just to see if their new inventory was priced lower than ours."
A person who shops.
"The shopper carefully compared prices before making a final decision at the checkout counter."
In plain English: A shopper is someone who goes to stores to buy things they need or want.
"The shopper grabbed a bag of groceries and headed for the exit."
The word shopper is a straightforward compound formed by adding the suffix -er to shop. It was first used in English to describe someone who shops, retaining its original meaning of a person engaged in that activity.