丸
まる · maru · JLPT N3 · noun
circle
🌕 maru sounds like marble: small, round and whole
丸 is 九 (nine) plus one extra dot: nine and one more makes a full round set. 丸い (marui) means round, and Japanese ship names traditionally end in -maru.
丸 — 九 nine + dot 丶
Originally a pictograph showing a small round object or pellet, depicting something that can be rolled. The modern form resembles 九 with a dot, but historically it derives from 仄 inverted, suggesting something tipping or rolling. It came to mean 'round ball,' 'pellet,' or 'pill.'