mendaciously

adv

1. In a lying or deceitful manner.

   “As a politician, he was very adept at speaking mendaciously in public.”

   “I don't think I'm going to buy what she just told me. Her gestures, eye movements, and hesitancy in her tone raised some substantial red flags. Therefore, I have reason to believe she was giving an excuse mendaciously. If you could've witnessed this, you'd know it too!”