This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
皟 is a rare character composed of 白 (white) and 責 (blame/responsibility). The exact historical development and original meaning are uncertain.
The kanji visually combines 白 (white) and 責 (blame). Imagine a pure white surface being blamed for a stain, but the meaning remains unclear.
For サク, imagine a sack (サク) of white rice being blamed for being too heavy: sack -> サク.