curtain
笰 centers on a covering or screen: a curtain, especially one made of bamboo or used in a carriage.
笰 combines 竹 (bamboo) with 弗, which likely contributes sound. The character originally referred to a bamboo screen or curtain used in carriages.
The bamboo top 竹 suggests a woven screen, and the lower part 弗 looks like threads or strips hanging down. Picture a bamboo curtain hanging in a doorway.
For フツ, imagine pulling aside a bamboo curtain with a sharp 'futs' sound as the strips slide along the rod: futs -> フツ.