ミドル級[midorukyuu] middleweight class
一級[ikkyuu] one grade
下級[kakyuu] lower grade
下級職[kakyuushoku] subordinate post
下級審[kakyuushin] lower court

下級生[kakyuusei] underclassmen
下層階級[kasoukaikyuu] proletariat
仮進級[karishinkyuu] conditional promotion
階級[kaikyuu] (social) class
階級章[kaikyuushou] rank insignia

高が[takaga] it's only ... (something)
意気軒高[ikikenkou] in high spirits
異常高温[ijoukouon] abnormally high temperatures
一斉高[isseidaka] all-round (market) advance
雲高[unkou] height of clouds

円高[endaka] high-valued yen
価値高い[kachitakai] valuable
可能性が高い[kanouseigatakai] very likely
勘定高い[kanjoudakai] calculating
気高い[kedakai] sublime