A person or animal involved in producing dung, or a vehicle used to spread dung on fields.
From 'dung' (Old English dung, feces) + '-er' (agent noun suffix). Can refer to either a producer of dung or a tool/implement used in dung spreading.
Medieval farmers would have said 'hire a dunger to spread manure'—the word shows a practical, unsqueamish attitude toward bodily functions that modern euphemistic language has mostly replaced with clinical terms.
Complete word intelligence in one call. Free tier — 50 lookups/day.