pecos pecopteroid • pecos river · · · Info · Definitions · Characters · · pecos · · Text Latin · · Script 5 · · Length 2 · · Syllables Definitions · · · (noun) a tributary of the Rio Grande that flows southeastward from New Mexico through western Texas. Synonyms: Pecos, Pecos River. · · Noun Definition 1 Characters · · c latin small letter c U+0063 e latin small letter e U+0065 o latin small letter o U+006F p latin small letter p U+0070 s latin small letter s U+0073