I've heard a few times the following expression and I'd like to know what doesthat mean : "to cross the wire".


Perhaps you are thinking of the idiom 'to get one's wires crosed'.

Have a look here. http://www.usingenglish.com/reference/idioms/get+your+wires+crossed.html

The reference Clive gave refers to miscommunications between people,
but the expression can also refer to any error you make as an individual - getting on the wrong bus, going to class on the wrong day, etc.
It applies most perfectly to miswiring a piece of equipment, especially swapping the polarity.

There's also "to cross the line," which is to go beyond the imaginary bounds of proper behavior.
Students: Are you brave enough to let our tutors analyse your pronunciation?
In the context of marketing communications, crossing the wire refers to the time at which a press release is distributed to a list of channels. It differentiates from the time at which the release is queued to be released since press releases are scheduled ahead of time.
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