variant spelling
A different accepted spelling of the same word (colour/color, catalogue/catalog).
homophone
A word that sounds like another but has a different meaning and spelling (site/cite/sight).
morpheme
The smallest unit of meaning in a word: a root, prefix or suffix.
etymology
The origin and history of a word.
connotation
The feelings and associations a word carries beyond its dictionary meaning (its denotation).
register
The level of formality of language: formal, neutral or informal.
academic vocabulary
Words used across school subjects for analysis and argument, such as analyze, significant, ambiguous, juxtapose.