investigate
覈 centers on thorough examination: investigating something closely to uncover the truth.
覈 combines 覀 (a variant of 西, possibly suggesting covering or examining) with 敫, which likely contributes a phonetic element. The exact historical development is uncertain.
The top 覀 looks like a cover being lifted, and the bottom 敫 suggests a hand holding a tool. Picture uncovering something and using a tool to investigate every detail.
For カク, imagine a detective putting on a cap and saying 'I'll crack this case!' as they investigate: cap + crack -> カク.
considering and examining; pondering and investigating