consonant
"Consonant" has two main meanings — one you probably know from learning the alphabet, and one that is more formal and less common. Let's look at both.
In the alphabet, every letter is either a vowel (a, e, i, o, u) or a consonant. Consonants are all the other letters — like b, c, d, f, g, and so on. When you say a consonant sound, your mouth, lips, or tongue block or restrict the flow of air in some way. For example, when you say 'p', your lips press together and then release a small burst of air.
language and linguistics, everyday education · Modern, widely used
This is a more formal use of the word. When something is consonant with something else, it fits well with it — it matches, agrees, or is consistent with it. Think of it like two puzzle pieces that go together perfectly. You will mostly see this in formal writing or academic texts.
formal writing, academic and professional language · Formal, more common in older or academic texts · figurative