1. to sell something at a lower price than a competitor
2. to present or promote something as less valuable or impressive than it actually is

Examples

• The discount store can undersell the department store by 30%.
• Local farmers undersell the grocery chains at the market.
• Don’t undersell your achievements on your resume.
• She tends to undersell her artistic talents.
• The company decided to undersell competitors to gain market share.
• He always undersells himself in job interviews.
• Online retailers often undersell brick-and-mortar stores.