No. A simile compares one thing to another. Therefore no one word by itself can be a simile and so the word "as" is not a simile. However the word "as" often forms part of a simile, for example: "he is as brave as a lion".
Yes, "nice as a cockroach" is a simile because it compares the quality of being "nice" to a cockroach using the word "as." Similes typically use "like" or "as" to draw comparisons, and in this case, the phrase suggests that the notion of being nice is as surprising or unexpected as associating a cockroach with something pleasant. This creates a vivid and somewhat humorous contrast.
A simile is a type of figurative language.
a simile foe wondrous
what is a simile for benifits
As dunb is not a word in English there is no simile for it.
a
Like word is mostly used for identifying a simile. It is a word that is used for comparison.
A metaphor
it can be sometimes. for example, 'she was a brave as a lion'. a lion is a noun. but it also doesn't have to be. for example, 'she was like a dream'. a dream isn't real.
The sentence 'Stubborn as a mule' is a simile as it contains the word 'as' which makes it a comparison.
Here's three antonyms for the word "simile"; difference, dissimilarity, unlikeness