up in the air

/AH1 P IH0 N DH AH0 EH1 R/
adjective
  1. 1

    Not yet resolved, finished, answered, decided or certain.

    โ€œI think I can do it quickly, but the exact schedule is still up in the air.โ€

Source: https://en.wiktionary.org/wiki/up%20in%20the%20air