to fabricate, to trump up
揑 centers on creating something false or deceptive: fabricating a story or trumping up charges. The idea is making something up that isn't real.
揑 is a rare character. It combines the hand radical 扌 with a phonetic component historically related to 臼 and 工, but the exact origin is uncertain. The modern form likely developed as a phono-semantic compound for fabricating or making up.
A hand 扌 working over a mortar 臼 and a tool 工 suggests mixing and shaping something by hand—like kneading dough or fabricating a story from raw materials.
For ゲツ, imagine a person fabricating a story about getting a new pet: 'get' sounds like ゲツ, and the hand is busy making up the tale.