The root, rosh means start or beginning. Great insight can be seen in adding the meanings of the letters to the word.
Bet means house.
This can be translated to include not only a building that one lives in, but the entire family including servants and one's possessions. It would then be pronounced Yeresh in which case it becomes inheritance. Shin is said to represent a tooth. It has the appearance of a molar which is used for chewing. It is the first letter in Shaddai meaning Self Sufficient.