In Theravada Buddhist context, a samanera (Pali: sāmaṇera, female: samaneri) can be translated as novice monk. It literally means 'small samana', or small renunciate, where 'small' has the meaning of boy or girl.
In the Vinaya (monastic discipline), a man under the age of 20 cannot ordain as a bhikkhu, but can ordain as a samanera. The female counterpart of the samanera is the samaneri. Samaneras and samaneris keep the 10 precepts as their code of behavior, and are devoted to the Buddhist religious life.
After a year or at the age of 20, a samanera will be considered for the higher Bhikkhu or Bhikkhuni ordination (Pali: upasampada). Some monasteries will require people who want to ordain as a monk to be a novice for a set period of time, as a period of preparation and familiarization.