He was appointed as the executive officer responsible for strategic planning.

executive 来自动词 execute（执行），加上形容词后缀 -ive 构成形容词，表示"执行的、管理的"。 officer 是名词，来自 office（办公室、职位）加后缀 -er，指"担任特定职务的人"。 executive officer 指"执行官"，是负责执行和管理的高级职位。