1. superlative form of plunky; having a dull, hollow sound; making a plunk sound
Usage: informal; often used to describe musical instruments or objects that produce a characteristic hollow or muted tone
2. superlative form of plunky; most lacking in courage or spirit; most timid or weak
Usage: informal; chiefly North American

Examples

• That old guitar has the plunkiest sound of any instrument in the pawn shop.
• He gave the plunkiest performance of the entire competition.
• The plunkiest notes came from the broken piano in the basement.
• She made the plunkiest excuse for missing the meeting.
• Of all the string instruments, that one produces the plunkiest tone.