How to get this puzzle's final word - Answers with 21 Letters

Question:

How to get this puzzle's final word

Answer:

PUTNINELETTERSINORDER

Length:

Similar Crossword Questions:

Final (and a word that can precede the first word of this puzzle's longest answers)
Fitting final answer for this puzzle?
Certain word puzzle
Kid Rock song that's the final word?
Show whose final episode aired 2/28/83, and this puzzle's theme
"West Side Story" song, or a hoped-for response after experiencing the transition in this puzzle's word ladder
Final word of a budgeting quip
Word that can come before the last word of this puzzle's longest entries
Word that has two diametrically opposed meanings (like this puzzle's eight theme entries)
Auctioneer's final word, almost
Magician, and word whose ten letters make up every answer in this puzzle
Word form made with the big letter depicted in this puzzle's diagram (this letter is entirely absent from the solution)
Word puzzle enjoyed by Queen Victoria
Word that can precede the first word of the six longest puzzle answers
Prevalent word in this puzzle
Word that can follow the first word of this puzzle's four longest answers
Angle (and a three-word hint to this puzzle's theme)
Word hidden four times in this puzzle
Buffoon in modern-day slang, and word hidden five times in this puzzle
First word across in the first-ever crossword (1913) and the first of a dozen appearances of the word in this puzzle's grid, written word search-style (left, right, down, and diagonally) ... Can you f
Word that precedes six other answers in this puzzle
Action hero's garb, and what each first word in this puzzle's four longest answers is
Word that may precede twelve words in this puzzle's grid
Threatener's final word?
Word with eye or final