surreptitious
sur-up-TISH-usadjMeaning done secretly so as not to be noticed
Memory hook SUR (= SUB): UNDER the table. When Mom turns to the stove, Kai sneaks his carrots under the table to the dog; the quick, secret handoff is surreptitious.
Kai slipped a surreptitious carrot to the dog under the table.
In context During the long speech, Rosa took a surreptitious look at her phone, tilting it below the table so the speaker would not notice.
Similar secret, sneaky, sly, underhand
Opposite open, obvious, blatant
From Latin surripere, “to snatch secretly”: sub- (under, secretly) + rapere (to seize).