From CHAT GPT:

Certainly, here are words starting with the letter "I" that can connote negative meanings:

Ignominious: Deserving or causing public disgrace or shame.

Inimical: Hostile; harmful in effect.

Iniquitous: Grossly unfair and morally wrong.

Invasive: Tending to intrude or encroach, especially in a disruptive or undesirable way.

Invidious: Likely to arouse resentment or anger in others.

Irresponsible: Lacking a sense of responsibility; careless.

Insidious: Proceeding in a gradual, subtle way, but with harmful effects.

Indolent: Wanting to avoid activity or work; lazy.

Intractable: Hard to control or deal with; difficult or stubborn.

Insipid: Lacking flavor; dull; not at all stimulating.

Inefficacious: Not producing the desired effect; ineffective.

Intransigent: Unwilling or refusing to change one's views or to agree about something.

Intolerant: Not tolerant of views, beliefs, or behavior that differ from one's own.

Incorrigible: Not able to be corrected, improved, or reformed.

Inopportune: Occurring at an inconvenient or inappropriate time.

Inculpate: To accuse or blame.

Illicit: Forbidden by law, rules, or custom.

Inane: Lacking sense or meaning; silly.

Insolvent: Unable to pay debts owed.

Impudent: Not showing due respect for another person; impertinent.

My favorite is: incontinence