This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 褁 is uncertain. It visually combines 衣 (clothing) with an upper component resembling 果 or a related form, but the original semantic and phonetic roles are unclear.
The kanji shows clothing 衣 with a fruit-like top. Imagine wrapping fruit in cloth to carry it, but remember the actual meaning is uncertain.
For セキ, picture a sack (ふくろ) made of cloth tied with a string: the string's quick 'seki' sound cues セキ as you pull it tight.