The professional lexicons of middle school mathematics teachers in communities around the world were documented as part of The International Classroom Lexicon Project. This vocabulary captured teachers' naming of classroom pedagogical practice. Reported in this paper are attributes of the lexicons of teachers from Australia and Chile. A comparison of the lexical items revealed commonalities and differences in the named phenomena and in the schema employed for their organisational structure. The analysis revealed differences attributable to cultural and contextual factors. A categorisation system was developed to classify the complexity of similarity of lexical items of one lexicon with another.