CELP stands for Code Excited Linear Prediction, a type of compression algorithm for speech signals. When it comes to synonyms for CELP, we could look at terms related to speech compression or audio coding. For instance, we could mention other forms of audio compression like MP3, AAC, OGG, or Opus. However, these formats are not based on the same principles as CELP. Another possibility is to refer to more technical terms related to signal processing and digital communication, such as transform coding, quantization, or bit rate reduction. Finally, one could also use synonyms for the concept of prediction, such as forecasting, estimation, projection or anticipation.