This is the 396th most frequent Arabic word.
مسؤول
Responsible; official.
Here, 'مسؤول' indicates the teacher's responsibility and duty to explain the lesson.
المعلم هو المسؤول عن شرح الدرس.
The teacher is responsible for explaining the lesson.
In this context, 'مسؤول' refers to an individual who holds an official position within an organization or institution.
الشخص الذي يعمل في الحكومة يعتبر مسؤولاً.
A person who works in the government is considered an official.
Here, 'مسؤول' is used to denote personal accountability or responsibility for one's actions or decisions.