Strong, muscular, or heavily built; having lots of substance or being substantial and impressive.
From 'beef' (meat from cattle), with the suffix '-y', originally referring to physical robustness from consuming meat, extended to anything substantial.
'Beefy' shows how food shaped language—in times of protein scarcity, people who ate beef were visibly stronger, so the word became synonymous with strength and power itself.
Complete word intelligence in one call. Free tier — 50 lookups/day.