Code coverage means, how well your test set is covering your source code. i.e. to what extent is the source code covered by the set of Test cases. As mentioned in above answers, there are various coverage criteria, like paths, conditions, functions, statements, etc.
Chiasmus. Definition: Chiasmus is a specific type of parallelism. It consists of two parallel phrases in which corresponding words or phrases are placed in the opposite order.
What's a Chiasm? A chiasm (or chiasmus if you rather) is a writing style that uses a unique repetition pattern for clarification and/or emphasis. Chiasm is pronounced kyâ²-az-um. Often called the chiastic (kyâ²-az-tic) approach or the chiastic structure, this repetition form appears throughout the Bible yet it is not well known.