stored_word()
{
   if [ -z "$stored_words_count" ]
   then
      stored_words_count=$(wc -l < words.txt)
   fi
   number=$RANDOM
   let "number = number % stored_words_count + 1"
   tail +$number words.txt | head -1
}

init_stored_words()
{
   while read w
   do
      words[${#words[@]}]=$w
   done < words.txt
   stored_words_count=${#words[@]}
}
stored_word()
{
   [ -z "$stored_words_count" ] && init_stored_words
   number=$RANDOM
   let "number %= stored_words_count"
   echo  ${words[$number]}
}