His humility made him popular among his colleagues, as he never boasted about his achievements.

humility 是名词，来自形容词 humble（谦逊的），后缀 -ity 表示抽象名词性质。这个词指"谦逊、谦卑"的品质，表现为不骄傲自大、不炫耀自己的成就。