This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 竎 is uncertain. It visually combines 立 (stand) and 廾 (two hands), but the original meaning and component relationship are unclear.
With no clear meaning, picture a person standing (立) with both hands raised (廾) in a gesture of uncertainty, as if asking 'what does this mean?'
For フウ, imagine a strong wind (風, ふう) blowing the person's hands up while they stand: 風 -> フウ, and the wind leaves the meaning unclear.