A dash, rushing movement, or sudden attack made in opposition to or in response to another dash or attack.
From counter- (against, in response) + dash (sudden rush). Both elements are simple and ancient in English—dash derives from uncertain origins but was well-established by the 15th century, while counter- comes from Latin. The compound describes a reactive movement against an opponent's aggressive move.
In fencing and swordsmanship, a counterdash was a precise term for the riposte—your opponent lunges at you, you avoid and dash back at them in one flowing motion—which is why this word appears in historical combat manuals but almost never in modern English.
Complete word intelligence in one call. Free tier — 50 lookups/day.