If you found your way here to ask this question, you certainly can find a definition of what Flash is on The Internet :) Try Googling for 'definition of Adobe Flash' - I believe that will return your answer (you were missing the word 'Adobe' which is very important! Make sure you paraphrase and do not copy what you read word for word.
The best way to paraphrase is to read one paragraph at a time and then say what you read in your own words. Then write what you said and see if it makes sense. If it does, you got it! If it does not, try again until it sounds good.
Answers & Comments
If you found your way here to ask this question, you certainly can find a definition of what Flash is on The Internet :) Try Googling for 'definition of Adobe Flash' - I believe that will return your answer (you were missing the word 'Adobe' which is very important! Make sure you paraphrase and do not copy what you read word for word.
The best way to paraphrase is to read one paragraph at a time and then say what you read in your own words. Then write what you said and see if it makes sense. If it does, you got it! If it does not, try again until it sounds good.
Good luck!
Dave