Using Dynamic Memory allocation for arrays

How am I supposed to use dynamic memory allocations for arrays?

For example here is the following array in which i read individual words from a .txt file and save them word by word in the array:

Code:

char words[1000][15];

Here 1000 defines the number of words the array can save and each word may comprise of not more than 15 characters.

Now I want that that program should dynamically allocate the memory for the number of words it counts. For example, a .txt file may contain words greater that 1000. Now I want that the program should count the number of words and allocate the memory accordingly.

Since we cannot use a variable in place of [1000], I am completely blank at how to implement my logic. Please help me in this regard.