This is the 480th most frequent Arabic word.
هم
"هم" in Arabic means "they" (third person plural pronoun) or "worry/concern" depending on context.
The word 'هم' is a subject pronoun used to refer to a group of people (they) in the nominative case.
هم يدرسون في المدرسة.
They study at the school.
The word 'هم' is a pronoun functioning as a direct object referring to a group of people (them).
رأيتهم في السوق.
I saw them in the market.
The word 'هم' is a possessive pronoun attached to the noun 'مسؤولية' indicating possession by a group of people (their).