private
close-tiled
in petto
intimate
homely
privately
auricular
under the rose
have a word in someone's ear
have a quiet word
in secret
privateness
private message
in confidence
heart of hearts
esoteric
orarium
tête-à-tête
personal life
tutorship
prep school
tutelage
preparatory school
tuition
eavesdropping
eavesdropper
private language
seminary
autodidactically
secret
home school
head-to-head
class
tete-a-tete
private means
on the hush
coach
inquiry agent
tutor
private instructor
privy
inwardly
minicourse
inside
knowing
chamber
doggo
out of sight
in hiding
self-learning