Lexical Expansion is a recurring theme in historical linguistics and sociolinguistics. As far as we know, the present study is the first attempt to pursuit the subject through an experimental approach. The present dataset report the results of a lexical decision test applied to 32 anonymized subjects and based on loan words from English that accept affixes from Brazilian Portuguese (eg. clipagem, cropar), as well as for English and Brazilian Portuguese words, nonwords and pseudowords.