空転: idling

空転: to idle

区域: area, district

the way one feels unsettled due to fright / the way one is upset

(audio engineering) multitrack recording

The hiragana syllable ろ (ro). Its equivalent in katakana is ロ (ro). It is the forty-third syllable in the gojūon order; its position is ら行お段 (ra-gyō o-dan, “row ra, section o”).

炉: furnace, kiln

(endearing) denotes endearment

理論: a theory

論: theory, argument, view