His klutziness showed when he spilled the soy sauce bottle in the kitchen.

klutziness 是由名词 klutz（笨拙的人）加上后缀 -iness 构成的名词。klutz 来自意第绪语，原指"木头、木块"，引申为"笨拙的人"。后缀 -iness 表示性质或状态，所以 klutziness 指"笨拙的状态或特性"。