shear / sheer 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. 👇
shear: (noun) (physics) a deformation of an object in which parallel planes remain parallel but are shifted in a direction parallel to themselves. (noun) a large edge tool that cuts sheet metal by passing a blade through it. (verb) cut with shears. (verb) cut or cut through with shears. (verb) become deformed by forces tending to produce a shearing strain.
sheer: (verb) cause to sheer. (adverb) straight up or down without a break. (adverb) directly.
shear: sh·IH·r
sheer: sh·IH·r
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)