adj

• (not comparable) Moving or operating quickly, as a train not making local stops.
• (comparable) Specific or precise; directly and distinctly stated; not merely implied.
  "I gave him express instructions not to begin until I arrived, but he ignored me."
• (postpositive, retail) Providing a more limited but presumably faster service than a full or complete dealer of the same kind or type.
  "Tesco Express"

noun

• A mode of transportation, often a train, that travels quickly or directly, either on a regular schedule or as a special or excursion. Express trains often pass through stations along the way without stopping at them.
• (obsolete) A clear image or representation; an expression; a plain declaration.
  "And this [holy communion] being the great myſtery of Chriſtianity, and the onely remanent expreſſe of Chriſts ſacrifice on earth, it is moſt conſonant to the Analogy of the myſtery, that this commemorative ſacrifice be preſented by perſons as ſeparate, and diſtinct in our miniſtery, […]"

verb

• (transitive) To convey or communicate; to make known or explicit.
  "Words cannot express the love I feel for him."
• (transitive) To press, squeeze out (especially said of milk).
  "The people of his island of Rokovoko, it seems, at their wedding feasts express the fragrant water of young cocoanuts into a large stained calabash like a punchbowl […]"
• (biochemistry) To translate messenger RNA into protein.
• (biochemistry) To transcribe deoxyribonucleic acid into messenger RNA.
  "When a cell “expresses” a gene, it translates the DNA first into a signature messenger RNA (mRNA) sequence and subsequently into a chain of amino acids that forms a protein."

noun

• (obsolete) The action of conveying some idea using words or actions; communication, expression.
  "Whereby they discoursed in silence, and were intuitively understood from the theory of their expresses."
• (obsolete) A specific statement or instruction.
  "This Gentleman [...] caused a man to go down no less than a hundred fathom, with express to take notice whether it were hard or soft in the place where it groweth."