Final answer:
The type of marriage involving one man with two or more women is called polygyny, a form of polygamy which is more common in certain societies often for cultural and economic reasons.
Step-by-step explanation:
The type of marriage that specifically involves the marital union of one man to two or more women is known as polygyny. Polygamy is a broader term that denotes the practice of marrying multiple spouses and when it involves one man with multiple wives, it is specifically called polygyny. This marital practice is widely found across different societies, and while polygamy can also encompass polyandry (one woman married to multiple men), polygyny is by far the more prevalent form. Cultural and economic factors play a significant role in these marital arrangements, often related to the benefits of a larger workforce for labor-intensive tasks in agricultural communities or the creation of broader kinship bonds.