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Banking in Switzerland

Wikipedia

Swiss bank account (plural Swiss bank accounts)

1. (figurative) Any place considered safe or secure to put things in.
   • 2014, Lionel Marti, La famille dans le Proche-Orient ancien, page 567:

     It seems that not only parents, but also husbands could have used the dowry as a kind of Swiss bank account.

2. Used other than figuratively or idiomatically: see Swiss,‎ bank account.

• (any secure place): Swiss bank