Gdddk

Consider the example attached below, taken from the memoir package documentation.

I would like to be able to replicate how the words "lines" and "nearest" appear in the margins. For example, say I am defining Coulomb's Law, I would like "Coulomb's Law" to appear in the margin in a similar fashion when I write about it in the main body text.

EDIT: I would like to achieve this without the use of a list environment, which for example @Vinccool96 has provided.

EDIT 2: I would like the command to apply to a specific word in a body of text, and produce result as shown in the screenshot, while also retaining the word in the body of text without necessarily altering its in text appearance, just adding the word again in the margin with the texttt font.

It seems you simple want to write an important word into the margin of your document.

Please see the following MWE (important code marked with <=====)

documentclassarticle 

usepackageblindtext % <========================= to create dummy text
usepackageshowframe % <========= to visualize typing area and margins
newcommandmyimportant[1]%
 marginpartexttt#1#1% <========= text in margin same text in text



begindocument 
blindtext
blafasel myimportantword % <=========================================
blub blindtext 

enddocument

and its result:

Be careful: too many myimportant commands near to each other can result in ugly output ...

I uses the itemize environment with custom labels, the text is made with the texttt command:

documentclassarticle

begindocument

 beginitemize
 item[textttlines] This is similar to textttclassic, but results in a 
 smaller final value.
 item[textttnearest] The calculated value is the nearest to the given value
 while still maintaining the relationship
 enditemize

enddocument