amplify

Short definition from Wiktionary

Verb

1. 1
   To render larger, more extended, or more intense.
2. 2
   To enlarge by addition or commenting; to treat copiously by adding particulars, illustrations, etc.; to expand.
3. 3
   To increase the amplitude of something, especially of an electric current.
4. 4
   To add content that is not present in the source text to the target text, usually to improve the fluency of the translation.