nap, knap

Nap or nap means a short sleep break--
Grandpa likes to take a nap in the afternoon.
The baby wouldn't take a nap, and now he's cranky.

Nap also means the pile or plush of material such as velvet or corduroy--
If you use this pattern on material with a nap, make sure the pieces all go the same way.
The buttons left a mark in the velvet where the nap was crushed.

Knap or knap ( rhymes with nap ) means to break sharply, or to rap sharply, as when breaking stones into small pieces--
Try not to knap the stone with the flint.
The man plans to knap these stones into small landscaping rocks.

Now that you know that, you can say--
"It's hard to take a nap when I can hear the men knap stones in the yard."

Note--not to be confused with "nape", meaning the back of the neck--
He gave himself a haircut, but he couldn't shave the nape of his neck.