amendoins

Amendoins is masculine. While it is indeed a loanword from Arabic origin (likely from "al-mundí" or similar), the word actually entered Portuguese relatively recently (16th-17th century with the introduction of peanuts to Europe), not during the medieval period. The masculine gender may be influenced by the Arabic article "al-" (masculine) in the source form, though the gender assignment in Portuguese was ultimately conventional. The word's masculinity is not predictable from morphological rules but rather established through historical borrowing conventions.