developmental

UK: /dɪˌveləpˈmentl/

WordReference Random House Unabridged Dictionary of American English © 2026

de•vel•op•ment  (di vel′əp mənt), n. 

1. the act or process of developing;
   growth;
   progress:
   child development; economic development.
2. a significant consequence or event:
   recent developments in the field of science.
3. a developed state or form:
   Drama reached its highest development in the plays of Shakespeare.
4. Music and Dance the part of a movement or composition in which a theme or themes are developed.
5. Business a large group of private houses or of apartment houses, often of similar design, constructed as a unified community, esp. by a real-estate developer or government organization.
6. [Chess.] the act or process of developing chess pieces.
7. Mining the work of digging openings, as tunnels, raises, and winzes, to give access to new workings, and of erecting necessary structures.

• French développement
• develop + -ment, or 1745–55

de•vel′op•men′tal, de•vel′op•men′ta•ry, adj. 
de•vel′op•men′tal•ly, adv. 
Synonyms

• 1. expansion, elaboration, growth, evolution; unfolding, opening, maturing, maturation.
• 3. maturity, ripeness.
• 5. community, subdivision.

Antonyms

• 1. deterioration, disintegration.