An adjective to describe the nature of information used to blackmail someone

Question

In yesterday's Washington Examiner article, the word "kompromat" was used to describe a piece of "compromising information" Russia might have on Trump.

What I'm looking for is a less vague synonym to "compromising", a word you'd use to describe an information which would make a person look bad in other people's eyes. Not necessarily in a criminal way, so "incriminating" would be too strong and off-topic - more like in a general way, but still less formal and flat than "compromising".

Any ideas?

PS: I'm asking since I strongly believe I had seen an exact word I'm now looking for before - but now I just cannot recall it.

Answer 1

I believe the term that you may be looking for is undermining.

Collins provides a learner's definition of undermine and some examples:

If you undermine someone or undermine their position or authority, you make their authority or position less secure, often by indirect methods.

examples

She undermined him and destroyed his confidence in his own talent. [VERB noun]

The conversations were designed to undermine her authority. [VERB noun]

Hope this helps!

Answer 2

X had some unsavoury/unsavory information about Y.

ODO:

unsavoury (US unsavory)

ADJECTIVE

1.1 Disagreeable and unpleasant because morally disreputable.
‘an unsavoury reputation’

In usage:

https://www.google.com/search?q=%22unsavoury+information%22
https://www.google.com/search?q=%22unsavory+information%22

Also, unflattering.

X had some unflattering information about Y.

Cambridge:

unflattering
adjective UK, US
making someone look less attractive or seem worse than usual:

The book portrays her in a very unflattering light.

In Usage:

https://www.google.com/search?q=%22unflattering+information%22&oq=%22unflattering+information%22