Not precise (10)
(Other definitions for indefinite that I've seen before include "Like a" , "Vague" , "Unsettled" , "Not decided or not known" , "Loose" .)
'not precise' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for inexact that I've seen before include "Not precise, ambiguous" , "not precisely correct" , "Not quite accurate" , "Wide of the mark" , "estimated?" .)
(Other definitions for loose that I've seen before include "Freed" , "Vague -- insecure" , "Unrestricted" , "Grant freedom to" , "Untie; dissolute" .)