pentuple means synonym of quintuple in its various senses.
Etymology
From penta- (“five”) + -ple, from Ancient Greek πέντε (pénte, “five”) and Latin plus (“in sum”).
adj
- Synonym of quintuple in its various senses.
verb
- Synonym of quintuple: To multiply or be multiplied by five.“He gives the agents 50 gp and promises to pentuple it if they discover who's harassing his business.”