diffusion, scattering, spread / (physics) diffusion

to scatter, to spread

participation in planning, policy-making, etc.

to have a part, to take part in planning

thorax, chest

(zoology) chelicera

a self-appointed ruler / (historical, Edo period) a so-called “chivalrous man”, a gangster or gambler who stood against the samurai

the first volume in a two- or three-volume set

a thing, occasion, circumstances, detail, particular / act of (word used for the nominalization of verbs, adjectives, or phrases)

ruin; cause of one's trouble