itech.

Headword: 
itech.
Principal English Translation: 

in it; with it; from it; in contact with it; into it; next to it (as suffix); next to it (as independent word)

Orthographic Variants: 
ytech
IPAspelling: 
iːtetʃ
Alonso de Molina: 

Itech. en, enel o del.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, f. 42r.

Frances Karttunen: 

ĪTECH possessed form, prefixed with third person singular possessive Ī- next to, on, attached to something, someone / en, en él, o de él (M), junto a él, pegado a él (T) See –TECH.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 107.

Attestations from sources in English: 

itech çaliuhtica ycenmanca huerta tetla = adhering to and united with the Tetla orchard (Coyoacan, 1622)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 4, 66–67.

itech = next to (used in boundary descriptions, and in this way very similar to inahuac; itech açi and itech çaliuhtica mean reaches as far as and adheres to, abuts on.)
Rebecca Horn, Postconquest Coyoacan: Nahua-Spanish Relations in Central Mexico, 1519–1650 (Stanford: Stanford University Press, 1997), 156.

ytech caliuhtica = adhering to the house
çan no mochi ytech nicpohua = I leave it all up to (him)
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.

itech nicpohua, or ytech nicpohua = I assign it to (someone) -- this is an idiom that is seen especially in testaments
Rebecca Horn's notes from Nahuatl classes with James Lockhart, currently being harvested for this dictionary by Stephanie Wood.