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.
Definition of Parallelism. Parallelism is the usage of repeating words and forms to give pattern and rhythm to a passage in literature. Parallelism often either juxtaposes contrasting images or ideas so as to show their stark difference, or joins similar concepts to show their connection.