(mathematics, geometry) Euclidian space - a space where the prinicples of Euclidean geometry apply.

(electronics) vacuum tube

living space

outer space

(topology) topological space / (mathematics, physics) phase space

考え: thought, opinion

図鑑: An illustrated reference book, such as a field guide, bestiary, guide book, or picture book

監視網: surveillance network

寒天: Agar, agar-agar. / 寒点: The sensory cells of the skin that perceive cold. / 官展: An art exhibit hosted by the government. / 寛典: A generous favor; merciful treatment, a merciful sentence.

関与: taking part in / 干与: being concerned with