Similar words
nonne
nonne is slightly more informal or older; religieuse is the more standard term, and also separately means a cream puff pastry — both mean "nun."
Similar in other languages
Portuguese
freira
freira is the Portuguese word for the same thing — both mean "nun."
Portuguese
monja
monja is the Portuguese word for the same thing — both mean "nun."
Practice
1 What does religieuse mean?
nun
2 Fill the gap: La ___ enseigne à l'école.
Full sentence: La religieuse enseigne à l'école. (The nun teaches at the school.)
3 Which fingerprint chart matches religieuse?
religieuse: neutral register, common frequency, general domain, neutral connotation.