|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|1.||a person or thing that precedes and shows or announces someone or something to come; harbinger|
|2.||a predecessor or forerunner|
|3.||a chemical substance that gives rise to another more important substance|
|[C16: from Latin praecursor one who runs in front, from praecurrere, from prae in front + currere to run]|
precursor pre·cur·sor (prĭ-kûr'sər, prē'kûr'sər)
One that precedes and indicates something to come.
One that precedes another; a forerunner or predecessor.
A biochemical substance, such as an intermediate compound in a chain of enzymatic reactions, that gives rise to a more stable or definitive product.