In the air (5)
'in the air' is the definition.
(aloft means above or overhead)
This is all the clue.
(Other definitions for aloft that I've seen before include "In the air, overhead" , "Heading for heaven" , "Skyward" , "To great height" , "At a considerable height" .)
(Other definitions for undecided that I've seen before include "Dithering" , "Not certain" , "With mind not yet made up" , "In two minds" , "Irresolute" .)