This is the 390th most frequent French word.
devoir
"Devoir" means "to have to" or "must" as a verb, and "duty" or "homework" as a noun.
In this sentence, "dois" (a conjugated form of "devoir") signifies obligation or necessity, indicating what the speaker is required to do.
Je dois finir mes devoirs avant le dîner.
I must finish my homework before dinner.
Here, "devoir" is used in its infinitive form to indicate probability or a supposition about an event.
Il semble devoir pleuvoir ce soir.
It seems it must rain tonight.
In this instance, "devoir" functions as a noun, referring to a moral or societal obligation or responsibility.