When you're trying to convey that there isn't sufficient or adequate quantity of something, saying 'not enough' can become repetitive and dull. To make your language more interesting, you can use a variety of synonyms like insufficient, inadequate, meager, deficient, scarce, lacking, paltry, wanting, insufficient, or poor. All of these alternatives will help to convey your message of a shortfall in a more dynamic way. Additionally, if you're looking for a less negative term, you could switch to something like 'limited,' 'modest,' or 'restricted' instead of 'not enough.' Using different synonyms helps you to express the right emotion or feeling that is appropriate for the context you are writing in.