wain / wane are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
wain: (noun) English writer (1925-1994). (noun) large open farm wagon.
wane: (verb) become smaller. (verb) decrease in phase.
wain: w·EY·n
wane: w·EY·n
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)