have the advantage of someone
know of
unacquaintedly
you-know-who
whatstheirname
scrape acquaintance
withoutcha
behind someone's back
whatshisname
whatshisface
personless
incognito
chance acquaintance
unbeknown
stranger
unbeknownst
namelessly
unacquainted
stigmaless
know someone from Adam
no-name
gossip
bandy around
cold shoulder
snub
cut
strangerlike
nonstranger
by oneself
throw in at the deep end
nonacquaintance
facelessly
slip away
character
traitorless
backbiting
talk at
singleton
anonymously
forgotten
generic you
friendless
unknowledgeably
semiacquaintance
walk-in
dip out
nonvisitor
close to home
whosiewhatsit
unpatroned