non irritating (adjective) bland: mild, temperate
Sinonime: backdoor, backstairs, camouflaged, classified,
close,
confidential,
covert,
cryptic,
discreet, disguised, dissembled, dissimulated,
furtive, hush-hush, in ambush,
incognito, inside,
restricted,
secretive,
sly,
sneak,
sneaky,
stealthy, sub-rosa,
surreptitious, top secret, unacknowledged, under false pretense, under-the-table, underhanded
Antonime: aboveboard, known,
legal,
legitimate, public