Oracle-bone form depicts a hand (又) reaching down into the mouth of a cave (穴) - the same scene preserved on the right side of 探 and 深. Read shēn, 'to reach into the depths'. Standalone 罙 dropped out of everyday use; modern dictionaries treat it as an archaic phonetic stem rather than a living word.
usage
Recognise 罙 as the right half of 深 (deep, water + 罙) and 探 (probe, hand + 罙). It supplies sound and a clear semantic flavour of 'reaching deep'. Spotting this stem helps you remember why both characters cluster around the idea of penetrating into something.
Components
pictograph
罙shēn
phonetic stem; reach into the depths
Oracle-bone form depicts a hand reaching down into the mouth of a cave - reaching into a hidden depth. Standalone 罙 dropped out of everyday use; the modern shape is now an unanalyzable phonetic stem. You meet it as the right side of 探 probe and 深 deep, where it supplies sound and the 'reaching into something hidden' imagery.
Filed under radical 网 (wǎng, #122) by convention. 网 is not a separate component in 罙, so no strokes are highlighted.
