Therefore is defined as because something happened.(adverb)
An example of therefore is saying that you got a cold and then had to stay home from work.
See therefore in Webster's New World College Dictionary
Origin: ME ther fore: see there & foreas a result of this or that; for this or that reason; consequently; hence: often used as a conjunctive adverb
See therefore in American Heritage Dictionary 4
Origin: Middle English
Origin: : there, there; see there
Origin: + for, fore, fore; see for.
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