無限
むげん · mugen · JLPT N2 · noun
space
無 = without, 限 = limit: without a limit = infinite
無 (mu) means none or without, and 限 (gen) means limit or boundary. Put together, 無限 (mugen) means having no boundary, so it is infinite.
限 — mound radical 阝 + 艮 (phonetic)
限 combines the 阝 (mound/hill) radical on the left with 艮 on the right, which provides the sound. The mound element suggests a boundary or barrier formed by terrain, and the character came to mean 'limit' or 'boundary' — the edge one cannot cross.