nonplussed, three (in documents), going, coming, visiting, visit, be defeated, die, be madly in love, participate, take part in
参 centers on joining or entering a situation: participating, visiting, or coming/going to a place. The sense of 'three' is a formal numeral used in documents, and 'nonplussed' or 'be defeated' are extensions of being overwhelmed by involvement.
参 is the modern simplified form of 參. The older form is thought to combine 晶 (stars) with 㐱 (a person with flowing hair), suggesting a person under the stars, possibly related to the idea of joining or participating in a celestial gathering. The modern form simplifies the upper part.
The top part looks like a person with a hat or a gathering shape, and the bottom 彡 suggests flowing movement. Picture someone arriving at a gathering, flowing in to participate.
For サン, imagine participating in a sand castle contest: sand -> サン, and you join in the building.
participation; joining; entry
reference; consultation
participation in a war; going to war
reference (e.g. to a dictionary, passage, footnotes); consultation; comparison
entering (the marketplace); introducing (something) to the market; access
going and worshipping (at a shrine or temple); visit (to a shrine or temple to worship)
House of Councillors (upper house of the National Diet of Japan)
bringing; taking; carrying
House of Councillors (upper house of the National Diet of Japan)
carrot (Daucus carota)
to go; to come; to call
taking part (in planning); participation
attendance; participation; presence
staff officer; military staff
senior; veteran; old-timer
visit to a grave
road approaching a shrine
visit; inspection
visit (to a shrine, grave, etc.); worship
participation; taking part
surrender; submission; capitulation
secretary; councillor; councilor
councillor; councilor
participant; entrant; player; competitor