A tool or device used for breaking ground or pushing soil forward, or a person who works with their chest against something.
From 'breast' + '-er' (one who does). Could relate to pushing with the chest or working a particular tool.
In agricultural history, a 'breaster' might refer to someone using a specialized plow held against their body—a reminder that before machinery, human strength, leverage, and clever tool design were everything.
Complete word intelligence in one call. Free tier — 50 lookups/day.