天魚[amago] land-locked variety of red-spotted masu trout (Oncorhynchus masou ishikawae)
御天気[otenki] weather
コール天[kooruten] corded velveteen
破天連[pateren] Portuguese Jesuits (in Japan in the 16th century)
天鵝絨[tengajuu] velvet

悪天[akuten] bad weather
悪天候[akutenkou] bad weather
悪天使[akutenshi] evil angels
旭日昇天[kyokujitsushouten] full of vigor and vitality (like the rising sun) (vigour)
一天[itten] the whole sky

医界[ikai] medical world
医学界[igakukai] medical world
黄金世界[ougonsekai] utopia
下界[gekai] this world
花柳界[karyuukai] red-light district

界隈[kaiwai] neighborhood
界面[kaimen] interface
各界[kakkai] each field
学界[gakkai] academic or scientific world
官界[kankai] bureaucracy