If the following words are arranged according to English dictionary, which…

Dictionary (lexicographic) order compares words letter by letter from the left. At the first letter position where two words differ, the word whose letter falls later in the English alphabet (A to Z) is the one placed later in the list; if the letters compared so far are identical, the comparison moves to the next letter.

1. All four words - Clean, Clear, Client and Clown - begin with the same first two letters, C and l, so the ordering must be decided by the letters that follow this shared "Cl".

2. Clean and Clear continue with the letter e (giving "Clea"), Client continues with the letter i (giving "Cli"), and Clown continues with the letter o (giving "Clo").

3. In the English alphabet the letters occur in the order ... e ... i ... o ..., so a word whose point of difference is e is placed before a word whose point of difference is i, which in turn is placed before a word whose point of difference is o.

4. Clean and Clear must still be compared with each other because they share "Clea": Clean continues with n and Clear continues with r; since n comes before r in the alphabet, Clean is placed before Clear.

• Client - diverges from the shared "Cl" prefix with the letter i, which comes after e but before o, so Client is placed after both Clean and Clear but before Clown.

• Clean - shares "Clea" with Clear and diverges at the next letter with n, which comes before Clear's r, so Clean is placed before Clear.

• Clear - shares "Clea" with Clean but diverges at the next letter with r, which comes after Clean's n, so Clear is placed after Clean, though still before Client and Clown.

Putting these comparisons together gives the single order Clean, Clear, Client, Clown - the same order in which these four words would appear on an actual dictionary page, since every "Cle..." entry precedes every "Cli..." entry, which in turn precedes every "Clo..." entry.

The word that comes last in this order is Clown.