Similar words
siglo
Worth distinguishing: centenar is a hundred (of anything); siglo is a century, specifically a hundred years.
Similar in other languages
Portuguese
cem
cem is the Portuguese word for the same thing — both mean "hundred."
Practice
1 What does centenar mean?
hundred
2 Fill the gap: Vinieron un ___ de personas.
Full sentence: Vinieron un centenar de personas. (About a hundred people came.)
3 Which fingerprint chart matches centenar?
centenar: neutral register, common frequency, general domain, neutral connotation.