greave / grieve 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. 👇
greave: (noun) armor plate that protects legs below the knee.
grieve: (verb) feel grief. (verb) cause to feel sorrow.
greave: g·r·IY·v
grieve: g·r·IY·v
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)