What is the meaning of Zijn?

to be, to exist

Used to connect a noun to an adjective that describes it.

Used to form the perfect tense of the active voice of some verbs, together with a past participle.
Note: The perfect tense of most other verbs is formed using hebben.

Used to form the perfect tense of the passive voice, together with a past participle.
Note: The imperfect tense passive is formed using worden.

Used to form the continuous forms of various tenses, together with aan het or, in archaic style, with a present participle.

to go, to go on a trip and return

Used to indicate weather, temperature or some other general condition.

to be, to equal, to total, to amount to; used to indicate that the values on either side of an equation are the same.

third-person singular, masculine and neuter possessive pronoun: his, its

Alternative spelling of sijn

Source: wiktionary.org