(adj) means annoying in a particularly vulgar and cheeky way. To be rude, insulting, and offensive. It is often used to refer to something intentionally oversized or intentionally offensively loud. Bragging is considered obnoxious, as is intentionally disregarding a rule. Showing off your disregard for a rule or order. Being blatantly disrespectful of social norms and those who would enforce them.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

People who are overly loud, sometimes offensive, & almost always irritating; will give you the compulsion to tear your own ears off to shove them down their throat.

the kind of people u wanna shoot in the head..

Annoying; Pesky; Pain in the neck; Bothersome

annoying/demanding

–adjective
1. highly objectionable or offensive; odious: obnoxious behavior.
2. annoying or objectionable due to being a showoff or attracting undue attention to oneself: an obnoxious little brat.
3. Archaic. exposed or liable to harm, evil, or anything objectionable.
4. Obsolete. liable to punishment or censure; reprehensible.