Principal English Translation: 

hired hand, hired help, servant; something rented (see Karttunen); or, mercenary (see Molina)

Orthographic Variants: 
Alonso de Molina: 

tlaqueualli. alquilado, o mercenario.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 134r. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TLĀQUĒHUAL-LI hired help, paid servant; something rented / alquilado o mercenario (M), criado, mozo, servidor, siervo, peón, sirviente (Z), alquilado (Z) [(7)Zp.9,35,86,96,115,214]. In all but two attestations, Z marks the vowels of the second and third syllables long. In one the vowels of the first and third syllables are marked long, and in the other the vowels of the first and second are marked long. This last pattern is the only correct one if this item is derived from TLĀQUĒHU(A), as it is according to M’s gloss.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 294.

Attestations from sources in Spanish: 

Opehque in tiquiti tlaquhualtin ye ce metztli, ye ome metztli. = Empezaron a trabajar los peones (y fue pasando) un mes, dos meses. (s. XX, Milpa Alta)
Los cuentos en náhuatl de Doña Luz Jiménez, recop. Fernando Horcasitas y Sarah O. de Ford (México: UNAM, 1979), 94–95.