tehuehuelli.

Headword: 
tehuehuelli.
Principal English Translation: 

a small shield; possibly a metaphor for a fetus or the strength necessary for birth

(central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), chapter 28.

in tlacochtli, in tehuehuelli may be a difrasismo meaning war
(sixteenth century, Quauhtinchan)
Historia Tolteca-Chichimeca, eds. Paul Kirchhoff, Lina Odena Güemes, y Luis Reyes García (México: CISINAH, INAH-SEP, 1976), 166.

Orthographic Variants: 
tevevelli, teueuelli
Attestations from sources in English: 

May be a metaphoric reference to the unborn child, or to the strength needed for childbirth. See the Florentine Codex, Book 6, Chapter 28. In Chapter 29 we see that midwives and old women carried symbolic shields (here actually called "inchichimal") as they accompanied the mocihuaquetzqui into battle ("It was not play fighting, not plundering; when they fought, they truly made war.") and then to her burial place. In the thirty-third chapter we see a reference to the unborn daughter as possibly taking up "in chimalli, in tevevelli" (tehuehuelli).

vel xicmana in tevevelli: nochpuchtzin, noxocoiouh: ca tiquauhcioatl, xicnamjquj, qujtoznequj: ximotilinj, xicmotlaehecalvili in quauhcioatl, in cioacoatl, in qujlaztli = Seize well the little shield. My daughter, my youngest one, be thou a brave woman; face it—that is, bear down; imitate the brave one Ciuacoatl, Quilaztli (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 160.

Iavtle, iautle xoconcuj in mochimal, xoconcuj in tlacochtli, in tevevelli, in javiltiloca tonatiuh = O Yaotl, O Yaotl, take thy shield, take the spear, the little shield which is for the gladness of the sun (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 204.

Legend has it that Huitzilopochtli was born arrayed for war so that he could defeat his siblings, the Centzonhuitznahua (led by Coyolxauhqui). He was carrying a teueuelli, some darts, and his dart thrower, all blue in color. The dart thrower was called the xiuatlatl. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 3 -- The Origin of the Gods, Part IV, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1978), 3.

Attestations from sources in Spanish: 

…yn onechtemo yn teouatica yn tlachinoltica auh yn tlacochtli yn teueueli y nomaceual…. = …me buscan para la guerra y para el dardo y el teueuelli, que son mi merecimiento…. (Quauhtinchan, s. XVI)
Historia Tolteca-Chichimeca, eds. Paul Kirchhoff, Lina Odena Güemes, y Luis Reyes García (México: CISINAH, INAH-SEP, 1976), 197, 166.