What is "to dress up"

Dress \Dress\ (dr[e^]s), v. t. [imp. & p. p. Dressed (dr[e^]st) or Drest; p. pr. & vb. n. Dressing.] [OF. drecier to make straight, raise, set up, prepare, arrange, F. dresser, (assumed) LL. directiare, fr. L. dirigere, directum, to direct; dis- + regere to rule. See Right, and cf. Address, Adroit, Direct, Dirge.]

1. To direct; to put right or straight; to regulate; to order. [Obs.]

   At all times thou shalt bless God and pray Him to dress thy ways.
   --Chaucer.

   Note: Dress is used reflexively in Old English, in sense of ``to direct one's step; to address one's self.''

   To Grisild again will I me dresse.
   --Chaucer.

2. (Mil.) To arrange in exact continuity of line, as soldiers; commonly to adjust to a straight line and at proper distance; to align; as, to dress the ranks.

3. (Med.) To treat methodically with remedies, bandages, or curative appliances, as a sore, an ulcer, a wound, or a wounded or diseased part.

4. To adjust; to put in good order; to arrange; specifically: (a) To prepare for use; to fit for any use; to render suitable for an intended purpose; to get ready; as, to dress a slain animal; to dress meat; to dress leather or cloth; to dress or trim a lamp; to dress a garden; to dress a horse, by currying and rubbing; to dress grain, by cleansing it; in mining and metallurgy, to dress ores, by sorting and separating them.

   And the Lord God took the man, and put him into the garden of Eden to dress it.
   --Gen. ii. 1

5. When he dresseth the lamps he shall burn incense.
   --Ex. xxx. 7.

   Three hundred horses . . . smoothly dressed.
   --Dryden.

   Dressing their hair with the white sea flower.
   --Tennyson .

   If he felt obliged to expostulate, he might have dressed his censures in a kinder form.
   --Carlyle. (b) To cut to proper dimensions, or give proper shape to, as to a tool by hammering; also, to smooth or finish. (c) To put in proper condition by appareling, as the body; to put clothes upon; to apparel; to invest with garments or rich decorations; to clothe; to deck.

   Dressed myself in such humility. -- Shak.

   Prove that ever Idress myself handsome till thy return.
   --Shak. (d) To break and train for use, as a horse or other animal.

   To dress up or To dress out, to dress elaborately, artificially, or pompously. ``You see very often a king of England or France dressed up like a Julius C[ae]sar.''
   --Addison.

   To dress a ship (Naut.), to ornament her by hoisting the national colors at the peak and mastheads, and setting the jack forward; when dressed full, the signal flags and pennants are added.
   --Ham. Nav. Encyc.

   Syn: To attire; apparel; clothe; accouter; array; robe; rig; trim; deck; adorn; embellish.