groan, grown

Groan or groan mean to make a noise, usually brief and loud, as if in pain or despair--
He uttered a loud groan when he heard the news.
The poor dog fell over with a groan after he was hit by the car.
A thing may also groan, meaning make a loud, low, and brief noise--
That branch makes a groan every time there is a gust of wind.

Grown or grown ( rhymes with groan ) is a participle ( used with a helper verb ) of "grow", meaning to increase in size or to develop and mature--
My how you've grown!
The rose bush we planted last year has grown up over the trellis.
He was surprised to see how his bank account had grown.

Now that you know that, you can say--
"The poor woman let out a groan when she realized that her children had grown too big for their clothes."

Note--"growan" means decomposed granite, like rock turned to gravel--
Nothing will grow there; it is all growan and rock.
Not to be confused with "grow on", meaning, informally, to become familiar to, or to engage the affections of--
He seems like an old grouch, but he may grow on you.
"Grow in" means to increase in size while planted in something, or over time--
This shrub will grow in sandy soil.
He is waiting for his beard to grow in.