These all have legitimate indigenous origins, though in some causes the meanings have shifted. I'll do a quick summary for each. Feel free to ask follow up questions.

• Wampum is derived from the name of the channeled whelk, a sea snail native to the Atlantic coast of North America. The original word comes from one of the Algonquian languages of southern New England, usually attributed to the Narragansetts of modern-day Rhode Islands, but all the languages in this area are closely related so occasionally one of their neighbors will be credited as well. The shells of the channeled whelk was used to make white beads which, along with the white-and-purple shells of the quahog, were used as a form of pseudo-currency among the nations of the Northeast. The could be fashioned into long belts of beads, which became standardized units of trade, as well as ceremonial gifts and mnemonic devices. When Europeans arrived, the term wampum was adopted for all such beads and they became increasingly monetized. In early Boston, you could even pay a portion of your taxes with wampum.

• Teepee is derived from the Lakota & Dakota word thípi, which means generally a "a house or dwelling." Since the Lakota at the time of sustained Euro-American contact, like many other Plains nations, lived in conical tents that could be easily disassembled and moved, their word for a home was adopted into English as the word for that specific style of dwelling.

• Powwow is the word most removed from its original meaning of the ones on your list. The original powwows were an order of healing priests among the Algonquian nations of southern New England - again Narragansetts are often credited with originating the term, but it appears in reference to their neighbors as well. They're what later Euroamericans writers might refer to as "medicine men." In modern times, a powwow refers to a large, typically intertribal gathering for dancing, ceremonies, competition, and just plain fun, arising from pan-Indian solidarity movements in the late 1800s and early 1900s. Most of the modern powwow traditions have developed from antecedents among Plains cultures, but there are bits and pieces that can trace their origins elsewhere, and depending on which nation is organizing or hosting the powwow, you can see more of their influence than you might more generally.

• Peace Pipes, also known as calumets (from the French), are ceremonial pipes used to signify peaceful intentions. In the colonial era they were most commonly employed on the Plains and the western parts of the Eastern Woodlands (further east, a belt of wampum would fill a similar role). We have archaeological evidence for a variety of ceremonial pipes in the region going back thousands of years - even before tobacco began to be cultivated in the area. The historic tradition, however, is credited - at least by the Lakota - to the holy woman Ptesáŋwiŋ, circa 900CE.

• How is an easy one. It's derived from the Lakota word háu, which is a greeting used between two men.