It's merely (only) a scratch.
Merely saying that it is true does not necessarily make it so. Or: Well, not necessarily.
He was not bored he was merely looking for vandals on wikianswers.
He was merely a customer service representative.The changes merely had any impact.
His family merely perpetuated his lies.
I am not writing a sentence using that word.
a sentence using the word endotracheal
This is a sentence using the word aviator.
If you merely say just the one word "Hello" to your friend you are not even saying a sentence you are only using one word. If you said "Hello, Dolly, how are you? You are using a simplex sentence. If you said "Hello, Doll, I have not seen you in a long time and I was wondering how you were doing." That would be a compound sentence.
in his lectures he reveals himself to be a merely perfunctory speaker.
this is a sentence using the word armchair.
I am saying a sentence using the word collagen.