This is, plainly, a word with far too many n s in it.
Yes, there may be only three, but they do a lot of damage. A goose might be able to say consonant with some degree of elegance, but it's beyond human capabilities to utter the word without giving the impression of being in the throes of a heavy cold.
As a child, I pronounced this word consternant, and people kept correcting me.
But now I wonder if, subconsciously, I was just trying to make the word a better place.
Sunday Rest: consonant. Consonants are vocal sounds which involve the total or partial closure of the vocal tract.
The letter T does this with the tongue, but the letter P does it with the lips.
I don't know of any alternative to using this word apart from talking about more interesting things.
So on the whole I'd recommend that.