しーっ

A yellow face placing an index finger over pursed lips, as if issuing Shh! or Shush! for silence. Some platforms feature raised eyebrows. Apple’s design suggests the face is tilting back slightly. 

May convey silence, quiet, secrecy, and discreetness. May also create a sense of buzz and anticipation, e.g., an exclusive sneak peek or news scoop.

See also 🤐 Zipper-Mouth Face. Joins 🤗 Hugging Face, 🤔 Thinking Face, and 🤭 Face With Hand Over Mouth as one of the few smileys featuring hands.