crowd in on
nonjoiner
wannabe
unwelcome person
persona non grata
draw into
butt in
colonize
nonmember
contact person
foreigner
outsider
carry over
camp follower
sticks in a bundle are unbreakable
outgroup
invasion
pinch-hit
intrusive
checkmate
ally
intrude
fixate
omit
nonentrant
lacker
loner
community organizer
noncooperative
bootstrap
keep together
swerve
joiner
slip away
go in on
outmate
leave alone
support bubble
civilian
fall into the wrong hands
take part
unfellow
moocher
nonparticipant
nonsocially
listen in
nonparticipator
discontinuer
social alienation
bowl out
nonacquiescing
uninvitee
nonresistant
unsocial
lone hand
abhor
mamihlapinatapai
lone wolf
associate
stranger
vote with one's feet
pull up the drawbridge
eschew
antiparticipation
exclusory
exclusionist
disconnect
chair plug
hermit
uncombined
straight-out
leave someone to their own devices
foot voting
let
knobstick
want no part of
disally
tagger
want-away
interloper
make common cause
take one's ball and go home
out of it
bring to the table
can't help
yen
ache
passer
outsiderish
pine
languish
entirely
hold
outsiderly
on the outside, looking in
yearn
go along for the ride