investigate
査 centers on examining something closely to uncover facts: investigating, inspecting, or looking into a matter.
査 combines 木 (tree) with 且, which likely contributes the sound and may suggest examining or inspecting. The exact historical development is uncertain.
Picture a detective climbing a tree 木 to get a better view and inspect the area below 且: 査 means investigate.
For サ, imagine a detective investigating a suspicious sack under the tree: sack -> サ, and the detective is inspecting it closely.
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investigation; examination; inquiry; enquiry; survey
inspection (e.g. customs, factory); examination; test; check; scan (e.g. MRI, PET); audit
search (esp. in criminal investigations); investigation; inquiry; enquiry
judging; inspection; examination; investigation; review
inspection; audit; judgement; judgment
police officer; policeman; constable
probe; inquiry; enquiry; investigation
assessment (of value, damages, etc.); revision (of a budget)
close investigation; careful examination; scrutiny
examiner; investigator; inquisitor; agent
scan; scanning
inspection (for compliance); investigation (tax, etc.)
(national) census
peer review; refereeing
Board of Audit
examination; consideration; test; quiz
visa
inspector; examiner; auditor
inquiry; enquiry; hearing
Public Security Intelligence Agency