persuasiveness; skilled at persuasion
Describes a person who is good at convincing others, or the quality of being persuasive. Often used as a noun or na-adjective.
He is so persuasive that we can entrust him with tough negotiations.
I asked a persuasive person to convince my parents for me.
説得力 is the abstract power or force of persuasion, while 説得上手 describes a person's skill or the quality of being good at persuading.
Compound of 説得 (persuasion) and 上手 (skillful). The exact historical derivation is uncertain, but the meaning is transparent from its components.