IPA: /ˈstɒkˌhoʊldər/
KK: /ˈstɑkˌhoʊldər/
A person or entity that owns shares in a company, giving them a claim on part of the company's assets and earnings.
As a stockholder, she received dividends from the company's profits.
Stockholder → It is formed from "stock" (from Old English *stocc*, meaning a tree trunk or a supply) and "holder" (from Old English *holdan*, meaning to keep or possess). A stockholder is someone who possesses a share or supply of a company.
Think of someone who 'keeps' or 'possesses' ('holder') a 'supply' ('stock') in a company — that's what a stockholder is.