Principal English Translation:
the ending of many adjective-like substantives
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), 235.
Lockhart’s Nahuatl as Written:
-ti, -c pret. ending indicating pret. agentive. abs. pl. -queh, combining form -cā-. 235
Attestations from sources in English:
tetic = petrified, hard as a rock (tetl);
cuauhtic = tall (like a 'tree' cuahuitl);
tlīltic = black (like 'ink' tlīlli);
chichīltic = red (like 'chili pepper' chīlli);
coztic = yellow (what coztli means is not known for sure)
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 111.