hole-and-corner
adjective
• attempting to avoid public notice; secret.
• "a hole-and-corner wedding"
Similar:
secret,
secretive,
in secret,
private,
clandestine,
underhand,
surreptitious,
covert,
furtive,
devious,
stealthy,
sneaky,
backstairs,
closet,
undercover,
hugger-mugger,
cloak-and-dagger,
behind-the-scenes,
under-the-table,
under-the-counter,
black,
hush-hush,