1. a dock worker who loads and unloads ships
Usage: nautical; historical
2. a person who groups things together rather than separating them into distinct categories
Usage: academic; informal

Examples

• The lumpers worked through the night to unload the cargo ship.
• Experienced lumpers could handle heavy freight with remarkable efficiency.
• The port employed dozens of lumpers during the busy shipping season.
• In taxonomy, he was known as a lumper who preferred broad classifications.
• The debate between lumpers and splitters continues in scientific circles.
• As a lumper, she tends to see similarities rather than differences.