ardua

Ardua is primarily a linguistic term, representing the feminine form of the Latin adjective arduus, which means difficult, steep, or arduous. In classical Latin, arduus has masculine, feminine, and neuter forms—arduus, ardua, arduum—used to agree with the noun. For example, via ardua means “a difficult road.” The form ardua appears when the noun it modifies is feminine.

In modern Romance languages, cognate forms survive as inflected adjectives meaning arduous or difficult. In Portuguese, árdua is the standard feminine singular form of árduo and is used before feminine nouns, as in tarefa árdua (“a difficult task”). The term thus retains the sense of effort, challenge, or severity across contexts.

As a word, ardua is not generally used as a standalone noun in English-language writing; it is encountered chiefly in discussions of Latin grammar, Latin-to-Romance inflection, or in examples illustrating feminine agreement with feminine nouns. The etymology traces back to Proto-Italic roots related to strength and effort, with cognates appearing across Romance languages.