The hiragana syllable きゅ (kyu). Its equivalent in katakana is キュ (kyu).

昼食: lunch, middle meal of the day

黄昏: dusk / 後昆: posterity

気圧計: barometer

基礎: basis, foundation, groundwork / 起訴: litigation, prosecution / 稀疎: rarity

木曽: the area around the upper part of Kiso River, west of the Kiso Mountains; a Japanese surname

油断大敵: there's many a slip twixt cup and lip, carelessness is what will get you into trouble; security is the greatest enemy; Idleness is the devil's workshop

大敵: powerful enemy / 対敵: confronting the enemy

気温: air temperature, atmospheric temperature, ambient temperature / 基音: (music) fundamental pitch, ground note

共産主義: the doctrine of communism