Question: I am looking for a good antonym for reducing/simplifying equivalent fractions: 'reduce' and 'simplify' both make sense to me when dividing, but I'm struggling to name what it is we do when we multiply a fraction by 2/2, or 7/7, or any of their Unity Sisters! 

Ideas that came to mind: increasing? complexifying?

Answer: 
I thought the standard terminology was ***expanding*** fractions, at least it is in my language.

Some support for this term found by googling:

[Expanding and Reducing Fractions](https://www.wyzant.com/resources/lessons/math/elementary_math/fractions/expanding_and_reducing_fractions)

[Expanding Fractions](http://www.personal-math-online-help.com/expanding-fractions.html)
How about saying "find equivalent fractions to"? For example, to find equivalent fractions to $\frac13$ means giving examples of $\frac{n}{3n}$ for different values of integers $n$.

Now, if we are asked to find equivalent fractions to, say, $\frac69$, this would include $\frac23$ (which is in simplest form) and, say, $\frac{10}{15}$ (where the numerator $10$ is not an integer multiple of $6$) so perhaps more clarifications are needed if this is what you intend to mean.