広める
ひろめる · hiromeru · JLPT N3 · verb-ichidan
to propagate
📢 広 = wide, as in 広い hiroi; hiromeru = make it wide, spread it
Built from 広い (hiroi, wide). The -meru ending turns an adjective into make-it-so: 広める means to widen something, like your knowledge, or to spread it, like a rumour or a custom. Compare 広がる (hirogaru), where it spreads by itself.