Having a backbone; showing strength, courage, and firm moral character.
Compound adjective from 'backbone' plus the past participle suffix -ed, used metaphorically. Emerged from literal anatomical meaning to psychological meaning in English by the 1600s.
Calling someone 'backboned' means they have backbone in both the literal biological sense AND the metaphorical sense of integrity—it's a compliment suggesting they're not wishy-washy!
Complete word intelligence in one call. Free tier — 50 lookups/day.