Therefore is defined as because something happened.
An example of therefore is saying that you got a cold and then had to stay home from work.
Origin of thereforeMiddle English ther fore: see there and fore as a result of this or that; for this or that reason; consequently; hence: often used as a conjunctive adverb
For that reason or cause; consequently or hence.
Origin of thereforeMiddle English there there ; see there . for, fore fore ; see for .