This root-based dictionary of the Ilocano language is the most comprehensive dictionary produced of Ilocano (Iloko), the lingua franca of Northern Luzon, and historically the native language of the majority of Filipino immigrants to the United States.

The body of the dictionary includes entries for roots and affixes with illustrative sentences, idioms, common derivations, and scientific names (when applicable). Ilocano synonyms are also furnished when appropriate. Derived words that undergo morphological fusion are listed as separate entries to facilitate lexical searches. There is also an affix cross-reference list to help the beginning student recognize root words.

Unlike most dictionaries of Philippine languages, it has an extensive English to Ilocano section, information on the pre-Hispanic syllabary, and language maps of the Philippines showing where the largest concentration of Ilocano speakers reside.