Congratz... You just did!!! How can you use frost in a sentence?
There was frost on the ground
Last winter my pipes frosted up and I had no warer for months.
The sprout was killed by the late frost. The seeds were not able to sprout without moisture.
Jack Frost is nipping at your nose!
Lacy is an adjective. It is used to describe a noun. You could say, "There is frost on the window." Or you could say, "There is lacy frost on the window." In the second sentence, you have described the frost. You have compared it to lace.
In the sense that a phrase is a set of words that conveys a meaning, yes. "The frost was sharp." is a complete sentence. If you are using the term "phrase" to mean "an incomplete sentence" then, of course, it is not incomplete so, you should find a different word to describe it.
Stay out of that yard, or their dog might nip you. During winter time, Jack Frost may nip at your nose.
Yes, I would very much like to have another slice of pumpkin pie. There's a little frost on the pumpkin this morning.
"I thought I thaw a puddy tat.." I did, I did thee a puddy tat... or wait five minutes for the chicken to thaw after you take it out of the freezer.
If you don't protect the plants from frost it will die.
It's a compound sentence, with two independent clauses connected by the conjunction "and."
Very.