patca.

Headword: 
patca.
Principal English Translation: 

substitute; mistress or concubine (See Karttunen)

IPAspelling: 
pɑtkɑ
Frances Karttunen: 

PATCA substitute; mistress or concubine / de parte de, por parte de, en lugar de (Z for –ĪXPATCA), su querida (del hombre casado) (T) [(3)Tp.132,(2)Zp.77,94,158]. M has patcayotia 'to substitute for someone, to succeed someone in office.'
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 188.

Update from the author: Should patca be cross-referenced to patla?