нареч. secretly, surreptitiously;
on the quiet
уйти ~ steal* away;
~ от кого-л. without telling smb
нареч. secretly, in secret, surreptitiously, by stealth; on the quiet, on the sly разг.
тайком от кого-л. — without smb.'s knowledge; behind smb.'s back (в плохом смысле)
уйти тайком — to steal away/out