暗君[ankun] foolish ruler
我が君[wagakimi] my lord
君子[kunshi] man of virtue
君子豹変[kunshihyouhen] the wise readily adapt themselves to changed circumstances

君主[kunshu] ruler
君臣[kunshin] ruler and ruled
君たち[kimitachi] (used colloquially by young females) you (plural)
君臨[kunrin] reigning

乳幼児[nyuuyouji] infants
幼い[osanai] very young
幼馴染[osananajimi] childhood friend
幼魚[yougyo] fry (young fish)
幼形進化[youkeishinka] paedomorphosis

幼子[osanago] infant
幼児[youji] infant
幼児ポルノ[youjiporuno] child pornography
幼児語[youjigo] baby talk (like choo-choo for train, etc.)
幼時[youji] childhood