achi.

Headword: 
achi.
Principal English Translation: 

a little, a small amount; or, somehow (see Molina; and see our entry for achitzin)

Orthographic Variants: 
achitzi, achitzin, achito, achiton
IPAspelling: 
ɑtʃi
Alonso de Molina: 

Achi. un poco, o poca cosa, o en alguna manera. adverbio.
Alonso de Molina, Vocabulario en lengua mexicana y castellana, 1571, (www.idiez.org.mx), f. 2r.
çan achi. poca cosa, o vnpoquito. aduerbio.
Alonso de Molina, Vocabulario en lengua mexicana y castellana, 1571, (www.idiez.org.mx), f. 14r.

Frances Karttunen: 

ACHI a bit / un poco, o poca cosa, o en alguna manera (M) this appears to be an element in constructions where it has the contrary sense of ´a lot, more, very much,´ as in ACHIPA ´always,´ ACHICUAL-LI ´better.´ See the note with ACHĪC. In some, but not all, constructions this has a final glottal stop, ACHIH. See ACHIHTETZIN, ACHIHTŌN, ACHIHTZIN.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 2.

Horacio Carochi / English: 

achi = a bit, some
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), 71 n4, 496.

çā achi = very little is or was lacking to do (something)
Carochi/Lockhart, 403.

Sometimes retains final glottal stop internally.
Carochi/Lockhart, 354 n4.

Lockhart’s Nahuatl as Written: 

achi = a little, some, a good deal
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), 210.

Attestations from sources in English: 

In a comparative statement, achi and oc achi mean more...than.
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.

rather something, somewhat, almost
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.

Attestations from sources in Spanish: 

achi'toton = muy poquito
Ver: Náhuatl clásico. El recurso de la evaluación. http://www.nawatl.com/es/book/29.aspx.

IDIEZ traduc. inglés: 
1. part of s.t.; 2. to do s.t. a little; 3. to do s.t. more quickly.
IDIEZ def. náhuatl: 
1. Pilchenetzin ce tlamantli. "¿Ticnequi achi nopiltlacual?" 2. Mochihua quentzin chicahuac ce tlamantli. “Quemman niicihui, achi nimotlaloa huan achi zan ninehnemi. ” 3. Quen mochichua ce tlamantli quemman monequi ma onmotlatocchihua. “Achi xiicihui tlan titlaoya para axcanah tihuahcahuazceh nican. ”