Purpose: There are many aspects of words that can influence our lexical processing, and the words we are exposed to influence our opportunities for language and reading development. The purpose of this study is to establish a more comprehensive understanding of the lexical challenges and opportunities students face. Method: We explore the latent relationships of word features across three established word lists--the General Service List, Academic Word List, and discipline-specific word lists from the Academic Vocabulary List. We fit exploratory factor models using 22 non-behavioral, empirical measures to three sets of vocabulary words: 2,060 high-frequency words, 1,051 general academic words, and 3,413 domain-specific words. Results: We found Frequency, Complexity, Proximity, Polysemy, and Diversity were largely stable factors across the sets of high-frequency and general academic words, but that the challenge facing learners is structurally different for domain-specific words. Conclusion: Despite substantial stability, there are important differences in the latent lexical features that learners encounter. We discuss these results and provide our latent factor estimates for words in our sample.