タン, はし, は, はた, ばた, はな, ただし, みず
edge, origin, end, point, border, verge, cape
JLPT1 G7 S14 F960
As per 耑# (neatly aligned) + 立 stand → stand in neat alignment. This meaning dropped, with 端 acquiring the borrowed meaning *end* via the original sense of 耑 (cloth hanging in neat alignment → the ends of a piece of cloth) → *edge*; *tip*; *side* → *fraction*; *portion*. Also, *vicinity* (← beside; around ← side) and *rectitude* → *right*.
[Full Kanji Etymology List]