Mysql/php database performance question

Hi, I got a question about using Mysql databases. I load textdata in VARCHAR colums up to size 50. I have about 5 of those columns. The last columns often contain empty cells. (data are wordmeanings, many words have only a 1 or 2meanings) What would be faster/better: - putting everything in a big varchar column (size 5x50) and PHP parsing them by comma after fetching or - keeping those 5 columns with a lot of empty cells in the last columns? Thanks, Simon