瓜二つ[urifutatsu] as alike as two melons (two peas in a pod)
天糸瓜[hechima] sponge gourd
水瓜[suika] watermelon
破瓜[haka] age 16 (girl)
破瓜病[hakabyou] hebephrenia (disorganized schizophrenia) (disorganised)

木瓜[boke] (Chinese) flowering quince
南瓜[kabocha] pumpkin
黄瓜[kyuuri] cucumber
天瓜粉[tenkafun] talcum powder

亜科[aka] subfamily
医科[ika] medical science
医科大学[ikadaigaku] medical school
家庭科[kateika] home economics
科名[kamei] family name

科する[kasuru] to inflict
科学[kagaku] science
科学院[kagakuin] science institute
科学技術[kagakugijutsu] science and technology