flag, banner, streamer
幟 centers on a piece of cloth used for display or signaling: a flag, banner, or streamer.
幟 combines 巾 (cloth) with 戠, which likely contributes the sound and may relate to marking or distinguishing, giving the idea of a cloth used as a signal flag.
The left side 巾 is a cloth, and the right side 戠 looks like a pole with a marker. Imagine a cloth attached to a pole, waving as a flag or banner.
For シ, picture a flag with the letter 'C' on it, waving in the wind: 'C' -> シ, and the flag is a banner.
nobori; long, narrow banner attached to a pole on one side and a horizontal rod along the top
Boys' Festival paper-carp streamers
kanji "large village" radical
flag; banner; ensign; emblem
making one's attitude (position, stand) clear; unfurling and clearly showing one's banner