If one learns without thinking, one will be lost in his learning. That is, if one does not think about what one learns, he will not arrive at the truth of it.

(grammar) a verbal conjugation class in which the verb stem ends in k-, with minor historical changes

(grammar) a verbal conjugation class in which the verb stem ends in s-

(Classical Japanese grammar) a verbal conjugation class in which the verb stem ends in r- with four irregular bases: -a, -i, -u, and -e

(rare) duality

two hundred and five (205) / Arabic numerals: 205 / Roman numerals: CCV

wielding two swords / a kind of grip in sumo wrestling

multiple citizenship

twenty years old

(inorganic chemistry) carbon dioxide