'Twas brillig and the slithy toves
  Did gyre and gimble in the wabe:
All mimsy were the borogoves,
  And the mome raths outgrabe.

"Beware the Jabberwock, my son!
  The jaws that bite, the claws that catch!
Beware the Jubjub bird, and shun
  The frumious Bandersnatch!"

He took his vorpal sword in hand:
  Long time the manxnome foe he sought --
So rested he by the Tumtum tree,
  And stood awhile in thought.

And, as in uffish thought he stood,
  The Jabberwock, with eyes of flame,
Came whiffling through the tulgey wood,
  And burbled as it came!

One, two! One, two! And through and through
  The vorpal blade went snicker-snack!
He left it dead, and with its head
  He went galumphing back.

"And hast thou slain the Jabberwock?
  Come to my arms, my beamish boy!
O frabjous day! Callooh! Callay!"
  He chortled in his joy.

'Twas brillig and the slithy toves
  Did gyre and gimble in the wabe:
All mimsy were the borogoves,
  And the mome raths outgrabe.

Annotations by Martin Gardner:

The OED lists “slithy” as a variant of “sleathy,” an obsolete word meaning slovenly, but later Humpty Dumpty gives “slithy” a different interpretation.

“Toves” should be pronounced to rhyme with “groves,” Carroll tells us in his preface to The Hunting ot the Snark.

The OED traces “gyre” back to 1420 as a word meaning to turn or whirl around. This agrees with Humpty Dumpty’s interpretation.

According to the OED, “gimble” is a variant spelling of “gimbal.” Gimbals are pivoted rings used for various purposes, such as suspending a ship’s compass so that it remains horizontal while the ship rolls. Humpty Dumpty makes it clear, however, that the verb “gimble” is here used in a different sense.

“Mimsy” is the first of eight nonsense words in Jabberwocky that are used again in The Hunting of the Snark. In Carroll’s time, according to the OED, “mimsey” meant “pring, prudish, contemptible.” Perhaps Carroll had this in mind.

In his preface to the Snark, Carroll writes: “The first ‘o’ in ‘borogoves’ is pronounced like the ‘o’ in ‘borrow.’ I have heard people give it the sound of ‘o’ in ‘worry.’ Such is Human Perversity.” The word is commonly mispronounced ‘borogroves’ by Carroll novitiates, and this misspelling even appears in some American editions of the book.

“Mome” has a number of obsolete meanings such as mother, a blockhead, a carping critic, a buffoon, none of which, judging from Humpty Dumpty’s interpretation, Carroll had in mind.

According to Humpty Dumpty, a ‘rath’ is a green pig but in Carroll’s day it was a well known old Irish word for an enclosure, usually a circular earthen wall, serving as a fort and place of residence for the head of a tribe.

‘Frumious’ is composed of ‘fuming’ and ‘furious.’

‘Manx’ was the Celtic name for the Isle of Man. Whether Carroll had this in mind when he coined the word ‘manxnome’ is unknown.

‘Tum-tum’ was a common colloquialism in Carroll’s day referring to the sound of a stringed instrument, especially when monotonously strummed.

In a letter, Carroll wrote that ‘uffish’ suggested to him “a state of mind when the voice is gruffish, the manner roughish and the temper huffish.

‘Gallumph’ - this Carrollian word has entered the OED as a combination of ‘gallop’ and ‘triumphant,’ meaning “to march on exultantly with irregular bounding movements.”

The OED traces the word ‘beamish’ back to 1530 as a variant of ‘beaming.’

‘Chortled’ - A Carrollian word that has made its way into the OED, where it is defined as a blend of ‘chuckle’ and ‘snort.’