1. suspended or supported from above; hanging below a supporting structure
Usage: often used in automotive and mechanical contexts
2. having a low-hanging jaw or protruding lower jaw
Usage: describing facial features

Examples

• The underslung chassis gave the race car a lower center of gravity.
• The truck featured an underslung spare tire mounted beneath the bed.
• His underslung jaw gave him a distinctive profile.
• The underslung bridge design allowed ships to pass underneath.
• The trailer had an underslung axle configuration for better stability.
• Her underslung lower lip made her appear to be pouting.