The word growth comes from the verb grow combined with the noun forming suffix -th.  It dates back to the 1550s in English, following the pattern of older words like health and stealth.  The base word comes from the Old English verb growan, meaning to flourish, sprout, or increase in size (used mostly for plants).  

According to the Oxford English Dictionary (OED), the noun growth was first used in English in the early 1500s, with the earliest recorded evidence dating from 1507–1508.  The verb "grow" was first used in English during the Old English period (before 1150).  The noun form of "grow" appeared much later, recorded in the mid-1500s (specifically 1536).  

Growth in storytelling is essential because it drives character arcs, creates meaningful emotional stakes, and transforms simple events into life lessons.  Without change or progress, a plot feels flat and characters fail to connect with the audience.  

Why Growth Matters:  
Deepening Connection: Readers or listeners care more when they see a hero face hard choices, learn from mistakes, and become a better person.  
Proving Theme: Growth acts as the living proof of the story's main message or moral lesson.  
Creating Conflict: Internal and external changes build tension and keep people curious about what happens next.  

Just the facts:

GROWTH Definition & Meaning - Merriam-Webster

GROWTH Synonyms: 85 Similar and Opposite Words | Merriam-Webster Thesaurus

GROW Definition & Meaning - Merriam-Webster

GROWING Definition & Meaning - Merriam-Webster

1 hour ago, drpaladin said:

Without growth, barbers and landscapers would go broke.

It is hard to imagine, no Figaro!!!  Or that in New York State alone, 45,000 landscaping businesses would be clipped!!!

While exact census counts specifically restricted to New York City limits fluctuate, New York State has over 45,000 landscaping businesses, with localized directories like Houzz listing roughly 1,500 active professional landscapers and design contractors in the immediate NYC metro area.

(Note: "The Barber of Seville" is a famous 1816 comic opera by Gioachino Rossini featuring the Figaro the barber, and has no direct numerical or thematic connection to the landscaping trade in New York City.)