Without a brief or without legal cases to defend; especially describing a lawyer without work.
From brief (a legal case or summary) + -less (suffix meaning 'without'). In legal contexts, a brief historically meant the cases a barrister had taken on.
British barristers historically lived in fear of being 'briefless'—it meant no income, no prestige, and no reason to wear the formal wig that was their badge of success.
Complete word intelligence in one call. Free tier — 50 lookups/day.