Sorry.

"Sorry" is a way to apologize for a small mistake you made. When you make a larger mistake and want to apologize more strongly, you can say "I'm sorry for ___ing":

I'm sorry for calling you by mistake.

However, in most situations this would be much too strong of an apology. So just saying "Sorry" is sometimes more appropriate:

Sorry I didn't call you back sooner.

(something) smeared

When something like ink or paint gets wiped or spread around on a surface, you say that it "smeared". Other things that can "smear" include:

• makeup
• toothpaste
• sauces

Here's how "smear" fits in a sentence:

 I accidentally smeared the ink.

My lipstick smeared.

There's pasta sauce smeared all over your shirt!

Another word with a similar meaning (but less common) is "smudged".