What is the meaning of Wesen?

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 warrn.

Used to form the continuous forms of various tenses, together with an't.

To go, to go on a trip and return.

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

To equal; used to indicate that the values on either side of an equation are the same, often used with gliek an.

To have the next turn in a game.

It is, be

to be

Alternative form of sīn

to be

Source: wiktionary.org