1726, "inconclusive," from in- (1) "not, opposite of" + decisive. Meaning "vacillating, characterized by indecision" is from 1775. Related: Indecisively; indecisiveness.
an indecisive manager brought the enterprise to a standstill
a long and indecisive war
indecisive boundaries running through mountains
indebted
indecency
indecent
indecipherable
indecision
indecisive
indeclinable
indecorous
indecorum
indeed
indefatigability