This expression means to be in a condition of oblivion, in an intermediate state. The usage alludes to the theological meaning of limbo, that is, a place outside hell and heaven to which unbaptized infants and the righteous who died before Christ's coming were traditionally consigned. The saying later came to take on the metaphorical meaning 'in prison'. In the seventeenth century the meaning was extended to the current usage.

Übersetzung:

in der Schwebe sein

Gegenteil(e)

The opposite of "to be in limbo" is "the die is cast".

Synonym(e):

You could also say: to go through an uncertain period of awaiting a decision.