Principal English Translation: 

concerning (see Lockhart and Carochi)

Horacio Carochi / English: 

-techpa = concerning
Horacio Carochi, S.J., Grammar of the Mexican language with an explanation of its adverbs (1645), translated and edited with commentary by James Lockhart, UCLA Latin American Studies Volume 89 (Stanford: Stanford University Press, UCLA Latin American Center Publications, 2001), 512, and see 84–85.

Lockhart’s Nahuatl as Written: 

relational word. relating to, about, concerning. meaning same as -techcopa. -tech, -pa.
James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 232.

Attestations from sources in English: 

ynic huel notechpa mihiyoti notechpa motlahuelquixti ynic notechpa motzoncuic = Therefore he indeed breathed ill on me, he loosed his anger on me; therefore he took vengeance on me. (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 2, 210–211.