IPA: /ˈmɜːr.tʃən.daɪ.zər/
KK: /ˈmɜrʧənˌdaɪzər/
A person or company that sells goods, especially in a retail setting.
The merchandiser arranged the products on the shelves to attract more customers.
Merchandiser → It is formed from "merchandise" (from Old French *marchandise*, meaning goods or wares) and "-er" (meaning a person who). A merchandiser is a person who deals with goods or wares.
Think of someone who handles 'goods' ('merchandise') — the '-er' just means a person. A merchandiser is someone who works with goods.