Garrulous
Excessively talkative; rambling
The garrulous taxi driver regaled us with stories of his encounters with celebrities.
Impertinent
Rude or disrespectful; showing a lack of proper manners
The child's impertinent question earned him a stern look from his teacher.
Inscrutable
Impossible to understand or explain; mysterious
The detective was baffled by the inscrutable symbols left at the crime scene.
Gregarious
Fond of the company of others; sociable
The children's gregarious nature made them popular at school.
Impregnable
Impossible to attack or defeat; secure
The castle stood impregnable on the hill, defying invaders for centuries.
Interminable
Seemingly endless; very long and tedious
The meeting seemed interminable, with no end in sight.
Imbroglio
A complicated or embarrassing situation; a muddle
The missing files caused an imbroglio within the company.
Indecisive
Unable to make a decision
The committee remained indecisive about the project proposal, delaying its progress.
Jocular
Playful and good-humored; funny
His jocular comments lightened the mood during the tense negotiations.
Impeccable
Flawless; faultless
The chef's presentation of the dish was impeccable.
Ineffable
Too great or mysterious to be expressed in words
The beauty of the Grand Canyon was an ineffable experience.
Laconic
Using few words; concise
The soldier's laconic report conveyed the urgency of the situation.