dominant

CEFR: C1-C2 /dom-i-nant/ [d.aa1.m.ah0.n.ah0.n.t]

The adjective "dominant" means most influential, having the greatest importance. The word “predominant” also means most influential, having the greatest importance, but native speakers wouldn't normally write or say it like that. Let's look at the following sentences where the two words are used interchangeably in the same context:

Example Sentences:

Newspapers play a dominant role in shaping public opinion.

Newspapers play a predominant role in shaping public opinion.

Both sentences are correct, but the first sentence is recommended. Why? Because we want to talk about the influence newspapers have, so we should use dominant. Here the meaning of dominant is “influential”.

Dominant also means most common. Like the word “dominant”, the word “predominant” also means 'most frequent' or 'most common'. Let's look at the following sentence where the two words are used interchangeably in the same context:

Example Sentences:

The most predominant color in this room is beige. (However, you could also say the dominant color in this room is beige).

So you could also say “the dominant color in this room is beige”.

However, in genetics, Only the adjective dominant can describe characteristics which are heritable even if only one parent carries the genes for those characteristics. For example:

Example Sentences:

(Correct!) Brown hair is a dominant trait. (This means brown hair is dominant)

(Incorrect!) Brown hair is a predominant trait.