complemental

US: (kom′plə men′tl)

WordReference Random House Unabridged Dictionary of American English © 2025

com•ple•men•tal  (kom′plə men′tl), adj. 

1. complementary;
   completing.
2. [Obs.]
   • accomplished.
   • ceremonious.
   • complimentary.

• complement + -al¹ 1595–1605

com′ple•men′tal•ly, adv. 

WordReference Random House Learner's Dictionary of American English © 2025

com•ple•men•ta•ry /ˌkɑmpləˈmɛntəri/  adj. 

1. complementing or completing.

WordReference Random House Unabridged Dictionary of American English © 2025

com•ple•men•ta•ry  (kom′plə men′tə rē, -trē), adj., n., pl. -ries. 
adj. 

1. forming a complement;
   completing.
2. complementing each other.

n. 

3. Fine Art See complementary color (def. 1).

• complement + -ary 1590–1600

com′ple•men′ta•ri•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

complementary / ˌkɒmplɪˈmɛntərɪ -trɪ/, complemental adjective

1. acting as or forming a complement; completing
2. forming a satisfactory or balanced whole
3. involving or using the treatments and techniques of complementary medicine

ˌcompleˈmentarily, ˌcompleˈmentally adverb

ˌcompleˈmentariness noun