Principal English Translation: 

a doll; a deity's image; female genitals; in Nahuatl hieroglyphs, the nenetl often provided a phonetic role for the syllable or particle -nen- (which has a negative meaning of useless or fruitless) or -ne-, the indefinite reflexive pronoun [See: Visual Lexicon of Aztec Hieroglyphs, entries for Nentequitl, Nenquizqui, Nenca, Nencauh, Zaocnen, etc.]

Alonso de Molina: 

nenetl. la natura de la muger, idolo, o muñeca de niños.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 68r. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

NENE-TL female genitals; image, doll / la natura de la mujer, ídolo, o muñeca de niños (M) In the sources for this dictionary this is only attested as the first element of NENEPIL-LI 'tongue' and the second element of CUAHUINENETZIN (the name of an insect). Since the two senses of this item are at some distance from each other and both distant from the senses of the attestations, it is possible that more than one lexical item is represented here, and they may differ phonologically.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 168.