undiplomatic

Indiscreet is a related term of undiplomatic.

As adjectives the difference between indiscreet and undiplomatic

is that indiscreet is not discreet; wanting in discretion while undiplomatic is not diplomatic or tactful.

Inexpedient is a related term of undiplomatic.

As adjectives the difference between inexpedient and undiplomatic

is that inexpedient is not expedient; not tending to promote a purpose; not tending to the end desired; inadvisable; unfit; improper; unsuitable to time and place; as, what is expedient at one time may be inexpedient at another while undiplomatic is not diplomatic or tactful.

As a noun taxonomy

is the science or the technique used to make a classification.

As an adjective undiplomatic is

not diplomatic or tactful.

As an adjective undiplomatic

is not diplomatic or tactful.

As an adverb undiplomatically is

in an undiplomatic way.