A skilled craftsperson who makes barrels; a cooper.
From barrel plus maker (one who makes), a transparent compound. Though barrelmaker exists, the older term 'cooper' (from Latin cuparium) is the traditional and more common term for this skilled trade.
Cooper is a surname borne by thousands of people—evidence that barrel-making was such a central medieval profession that family names were born from it, just like Smith, Miller, and Baker.
Complete word intelligence in one call. Free tier — 50 lookups/day.