You define it because its the fastest and the easiest.
You can define words such as words in a dictionary.
Like sweat swan and swamp.
Or west weather and weekend.
And call cafeteria and camel.
There are more than one thousand words to define.
Or blends digraphs trigraphs and dipthongs.
A
Some longer than average words that start and end with the same letter are:straightforwardnessexperiencemilitarismmulticulturalismexterminatesuperfluousnesscatastrophicarachnophobiacharacteristicdecaffeinateddisenfranchisedexcommunicategrandstandinggroundbreakinglackadaisicalnationalizationnewspaperwomanproprietorshipspontaneousnesstranscendentalisttranscriptionist
redderarmadacosmicdemanddeniedgazinggapinggaminglethalrenterrockerstatustalentwillowyearly
Alliteration is when words that follow each other start with the same letter. E.G: crazy car, bouncy bunny...
alliteration
Alliteration is the use of two or more words together that start with the same letter: "Simple statistics sometimes startle" "Digitalis is definitely deadly" "Girls gather gracefully, men make a mockery".
Algebra, alfalfa, ammonia, amnesia and antenna are 7 letter words. They begin and end with the letter a.
You may be thinking of a dictionary, but all the words in the chapter do not start with the same letter. All the words to be defined do, but the language of the definitions do not.
There can be words beginning with different letters without ruining the alliteration, but the more words that do start with the same letter, the stronger the alliteration.
mom yay rear dad
Alliteration.
Both words derive from the same word root, but 'definition' is a noun, and 'to define' is a verb.