Dictionary:

Roman

  (rō'mən)

1. 1. Of or relating to ancient or modern Rome or its people or culture.
   2. Of or relating to the Roman Empire.
2. 1. Of, relating to, or composed in the Latin language.
   2. Of or using the Latin alphabet.
3. Of or relating to the Roman Catholic Church.
4. Of or being an architectural style developed by the ancient Romans and characterized by the round arch as chief structural element, the vault, concrete masonry construction, and classical ornamentation.
5. roman Of or being a typestyle characterized by upright letters having serifs and vertical lines thicker than horizontal lines.

1. A native, inhabitant, or citizen of ancient or modern Rome.
2. The Italian language as spoken in Rome.
3. One belonging to the Roman Catholic Church.
4. roman Roman print or typestyle.
5. Romans (used with a sing. verb) (Abbr. Rom. or Rm) A book of the Bible.

[Middle English, from Old English Rōmān or from Old French romain, both from Latin Rōmānus, from Rōma, Rome.]

The noun has 2 meanings:

Meaning #1: a resident of modern Rome

Meaning #2: an inhabitant of the ancient Roman Empire

The adjective Roman has 4 meanings:

Meaning #1: relating to or characteristic of people of Rome
  Pertains to noun: Roman (meaning #1)

Meaning #2: of or relating to or characteristic of Rome (especially ancient Rome)
  Pertains to noun: Rome (meaning #1)

Meaning #3: characteristic of the modern type that most directly represents the type used in ancient Roman inscriptions
  Pertains to noun: roman (meaning #3)

Meaning #4: of or relating to or supporting Romanism
  Synonyms: r.c., Romanist, romish, Roman Catholic, popish, papist, papistic, papistical
  Pertains to noun: Romanism (meaning #1)