the definite singular being the same as the plural indefinite, does this happen only with neuter nouns?
O.K., so I guessed wrong. I put an "en" at the end of the word. Looks like this is another word that is the same, regardless of being singular or plural.
förbindelse is not right ?
No, that means "connection". It can be physical, as in a ferry route or a phone connection, or abstract, as in a romantic liaison - but it can never mean "wedding".