What is MBL? MBL stands for Mid Back Length. This is yet another reference to hair length in which the hair extends down to the midpoint in the back. POSTS RELATED TO THIS TERM Terminal Length – How Long Can Your Hair Actually Grow? How To Get 4b Hair To Waist Length In 3 Years 10 Reasons You Are At A Hair Length Plateau – Black Hair Information Related Posts:What is BSL?What Is APL?What is CBL?What is the LOC or LCO method?What Does DC Or DT Mean?What is SLS?What is HG?What is A TNC? TweetPinShare0 Shares Black Hair Information > Glossary > What is MBL?