Select the option that can be used as a one-word substitute for the given group of words.

One who collects stamps

Philatelist

The word that can be used as a one-word substitute for "one who collects stamps" is philatelist.

The other words in the options, numismatist, narcissist, and collector, do not mean the same thing.

• Numismatist is a person who collects coins or currency.
• Narcissist is a person who is excessively self-absorbed and has an inflated sense of their own importance.
• Collector is a person who collects things, such as stamps, coins, or baseball cards.

A philatelist is a person who collects stamps. The word "philatelist" comes from the Greek words "philos" (love) and "atelēs" (exemption from payment), which refers to the fact that stamps were originally used to exempt the bearer from paying postage.