underdressed (Adjective) — Inadequately or too informally clothed. ex. "She was underdressed for the hiking trip and suffered hypothermia"
underdressed (Verb) — Dress without sufficient warmth. ex. "She was underdressed for the hiking trip and suffered hypothermia"
underdressed (Verb) — Dress informally and casually. ex. "On Fridays, employees can underdress"