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