Someone who's benignant is goodhearted and kind. Your favorite teacher in elementary school was probably the most benignant of them all.
When you're describing a lovely, warm person you can call her benignant, or even describe someone with a particularly sweet face as looking benignant. Another way to use this adjective is as a less common way to say "benign," or not harmful, especially in a medical sense — a benignant tumor, for example, is one that won't hurt you. Benignant, in fact, comes from benign, simply adding the ant on the model of malignant, or "dangerous, infectious, or cancerous."