Two-timing

Two-timing can also refer to a mathematical technique of solving a second-order differential equation using two time variables, one identified as the "slow time", which provides the general movement of the background frame or course dynamics, and another called the "fast time", which captures the behavior of smaller, rapidly changing or oscillating structures.

Wikipedia does not have an article on "two-timing", but its sister project Wiktionary does:

Read the Wiktionary entry "two-timing"

You can also:

Search for Two-timing in Wikipedia to check for alternative titles or spellings.

Start the Two-timing article, using the Article Wizard if you wish, or add a request for it; but please remember that Wikipedia is not a dictionary.