mnemonic

n. 1. Something used to assist the memory, as an easily remembered acronym or verse. [ WordNet 1.5 ]

2. An abbreviated word that resembles the full word, used so as to be easily recognized; as, the CIDE uses ... tags as mnemnonics for an italicised word or field. [ PJC ]

In basic organic chemistry class, one may learn the mnenomic “Oh my, such good apple pie” to help remember the names of the dicarboxylic acids in increasing order of length, namely: oxalic, malonic, succinic, glutaric, adipic, and pimelic acids. (From L. Fieser's Organic Chemistry text).