From Middle English ut-, from Old English ūt- (also as ūta-, ūtan- ("from or on the outside, without"), as in ūtanweard ("outward, external")), from Proto-Germanic *ūt-.

1. External to, on the outside of

   outback

   outhouse

2. Toward the outside of, away from

   outcast

   outlead

   outflee

3. Forms verbs with the sense of surpassing or exceeding the prefixed word. This construction is productive.

   outdo

   outlast

   outmaneuver

   • c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act III, scene ii]:

     It out-Herods Herod. Pray you, avoid it.

4. Greater than

   outsize

   outrun

   outgrow

   By the end of the competition, Lisa's plant had outgrown its competitors, winning the competition.

5. Beyond

   The plant's leaves outgrew their box

6. Completely

   outfit

   outwork

• (outside) ex-, exo-, ecto-
• (away from) off-, ab-, apo-, de-, away, off
• (surpassing) (loose sense) supra-
• (greater than) supra-
• (beyond) trans-, para-, hyper-, ultra-, extra-, preter-

• (antonym(s) of “outside”): in-, intra-, en-/em-/im-, end-/endo-/ento-