This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
硺 combines 石 (stone) with 豖, which may have contributed sound. The exact historical development is uncertain, and the character is rare.
The left side is stone 石, and the right side 豖 looks like a pig 豕 with an extra stroke. Without a clear meaning, picture a stone pig statue—its purpose is a mystery.
For タク, imagine tapping a stone pig with a tack: tack -> タク, and the stone 石 makes a dull sound.