Deep down Definition 1 of 3Pro Tip 1/3Unspoken Truth Used when someone is hiding their true feelings or opinions. Deep down, she disagreed with the decision but remained silent. Pro Tip 2/3Emotional Conflict Shows a difference between what's shown and what's felt inside. He smiles often, but deep down, it's clear he's not happy. Pro Tip 3/3Revealing Honesty Implies honesty when someone admits their feelings to themselves. Deep down, I knew the job wasn't right for me.