sub ‧ lim ‧ i ‧ nal /sʌbˈlɪmən ə l, sʌbˈlɪmɪn ə l/ BrE AmE adjective
[ Date: 1800-1900 ; Language: Latin ; Origin: limen ; ⇨ ↑ sublime 1 ]
affecting your mind in a way that you are not conscious of:
a subliminal message
subliminal advertising (=with hidden messages and pictures in it)