greaves / grieves 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. 👇
greaves: (noun) the residue that remains after animal fat has been rendered.
grieves: (noun) intense sorrow caused by loss of a loved one (especially by death). (noun) something that causes great unhappiness.
greaves: g·r·IY·v·z
grieves: g·r·IY·v·z
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)