eccentric
adj.adj. describing someone who behaves in a strange or unusual way, but often in a funny or interesting way. It is usually used for people who are different but not dangerous.
adj. characterised by unconventional or slightly strange behaviour. Often carries a neutral or mildly positive connotation of individuality rather than a negative one of mental instability.
My neighbor is an eccentric man who wears pajamas to the grocery store.
The professor was known for his eccentric teaching style, which included singing his lectures and wearing historical costumes.
While his peers followed traditional career paths, he maintained an eccentric lifestyle, living in a converted lighthouse and dedicating his time to collecting rare mechanical clocks.
From Middle French excentrique, from Medieval Latin eccentricus, from Ancient Greek ἔκκεντρος (ékkentros, “not having the earth as the center of an orbit”), from ἐκ (ek, “out”) + κέντρον (kéntron, “point”). Equivalent to ex- + -centric.
Typically used to describe people, habits, or interests; can also describe orbits in a technical context to mean not perfectly circular.