セン, ひそ.む, もぐ.る, かく.れる, くぐ.る, ひそ.める

conceal, hide, lower (voice), hush

JLPT0 G13 S0 F5000

# is deep penetration + say/speech indicator → utterance that penetrates deeply. adds water → penetrate deep into water in diving/submerging → *dive/submerge* → *lurk*; *hide* (← lie in wait in deep concealment) → *conceal*; *secret*; *latent*. Also, *hush*, *lower one's voice*, and *get/crawl into* (becoming hidden). Note that there is no etymological relation between the Shinjitai and the character .

[Full Kanji Etymology List]