Intrude
Definition 1 of 4
Pro Tip 1/3
Unwanted Presence
Used when someone is where they're not supposed to be, often making others uncomfortable. He seemed to intrude at the party, standing awkwardly alone.
Pro Tip 2/3
Lack of Invitation
Highlights the absence of an invitation or right to join a situation or conversation. I felt like I'd intrude if I joined their dinner uninvited.
Pro Tip 3/3
Diplomatic Sensitivity
Often applicable in situations requiring tact or discretion to avoid offending others. I didn't want to intrude with my questions during their mourning.