Wordnet 3.0
ADJECTIVE (2)
1.
very uncertain;
- Example: "left everything up in the air"2.
not yet determined;
- Example: "plans are still up in the air"
WordNet (r) 3.0 (2006):
up in the air
adj 1: very uncertain; "left everything up in the air"
2: not yet determined; "plans are still up in the air"