unprincipled

adjectives

lacking principles or moral scruples
"freedom from coarse unprincipled calumny"- A.E.Stevenson
unprincipled
antonym
principled
see also
without scruples or principles
"unscrupulous politicos who would be happy to sell...their country in order to gain power"
unscrupulous
having little or no integrity
unprincipled
is similar to
lacking honor or integrity; deserving dishonor
"dishonorable in thought and deed"
dishonorable, dishonourable