Complex sentence: The term root cause has been used in professional journals as early as 1905, but the lack of a widely accepted definition after all this time indicates that there are significantly different interpretations of exactly what constitutes a root cause.
Split into simpler sentences: The term root cause has been used in professional journals as early as 1905. But the lack of a widely accepted definition after all this time indicates that there are significantly different interpretations of exactly what constitutes a root cause.