IPA: /ˈpɪkər/
KK: /ˈpɪkər/
A person or tool that selects or gathers items, often crops or fruits, or a musician who plays a stringed instrument by plucking the strings.
The apple picker worked all day in the orchard, collecting ripe fruit from the trees.
Picker → It is formed from "pick" (from Old English "piccan", meaning to choose or select) and "-er" (meaning a person who). A picker is a person who chooses or selects something.
Think of someone who 'chooses' ('pick') something — the '-er' just means a person. A picker is someone who selects.