Q

from The American Heritage® Dictionary of the English Language, 5th Edition.

• abbreviation quarter (of a year)
• abbreviation quarterly
• abbreviation Games queen
• abbreviation question

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The seventeenth letter of the English alphabet, called cue and written in the Latin script.
• noun The ordinal number seventeenth, derived from this letter of the English alphabet, called cue and written in the Latin script.
• abbreviation question or questions
• abbreviation quarter
• abbreviation the supposed common source of the Gospels of Mark and Luke (from German Quelle, source)
• abbreviation the Q factor in electronics
• abbreviation astronomy quasar
• abbreviation sports qualified
• abbreviation American Library Association Abbreviation for quarto, book size (25-30cm).
• abbreviation chess queen
• proper noun The pseudonym of Sir Arthur Quiller-Couch
• noun The seventeenth letter of the basic modern Latin alphabet.
• noun biochemistry IUPAC 1-letter abbreviation for glutamine