1. to go inland (whether or not uphill, to go up, climb, ascend, mount, rise; to fall, as one shadow on another. 2. to experience personally, or appear, as heat.
Generally in our Hawaiian islands, and many other island communities, I suppose, when you go inland you are more than likely ascending. This word is piʻi. When you go mountain climbing specifically, you "piʻi kuahiwi." When the tide rises it is called "piʻi ke kai" or literally, "the sea rises." Any form of ascending, whether it be climbing a tree or going up a bunkbed, would be called piʻi.
Piʻi is also the word used to describe a feeling that you get, particularly heat, cold, and emotion, such as "piʻi ka wela" the heat rises, for when you get angry. No kona huhū, piʻi ka ʻōlelo ʻino - because of his anger, evil words come forth. Piʻi ke anu - to get chills (literally it means the coldness rises). Piʻi ka ʻula - the redness rises (blushing).
Here are several ʻōlelo noʻeau using the word piʻi:
Piʻi ka ihu o ka naiʻa i ka makani - The nose of the dolphin rises toward the wind. (Said of one who is haughty.)
Piʻi mai nei i ka pali me he ʻaʻama lā - Climbs the cliff like an ʻaʻama crab (said of one who goes beyond the limit).