As a transitive verb (a verb with an object), shear means “to cut or clip, as hair or wool, from someone or something” or “to deprive of something as if by cutting,” while as an intransitive verb, it means “to become divided under the action of a shear.”
Teen who sheared vehicle in half has drunken criminal past
Sheringham’s Skye Hubbard has 12 inches of her hair shorn for charity
Norfolk Eastern Daily Press
‘Our propeller has just sheared off’: Plane lands safely in Australia amid extraordinary emergency
Shear may also be used as a noun referring to “a cutting implement similar or identical to a pair of scissors but typically larger.” In this sense, it is usually used in the plural form shears. It may also refer to “an action or stress resulting from applied forces that causes or tends to cause two contiguous parts of a body to slide relatively to each other in a direction parallel to their plane of contact.”
Shearing: Tony Coster set to hang up his shears
New Zealand Herald
Severe weather terms, what is “gate-to-gate” shear?
KOCO Oklahoma City
Pink goes the shears for fundraiser
Avon Valley Advocate
On the other hand, the term sheer can be used as different parts of speech. As a verb, it means “to deviate from a course.”
“The impact sheered the heavy metal spring at the front offside wheel with a bang so loud that you probably heard it back in Dumbarton.”
Scottish Daily Record
“It’s a spectacular sight as the carbon fiber front-end sheers off when the car takes flight…”
“The county filled in a drop-off sheered away by the floodwaters with boulders…”
When used as an adjective, it means “nothing other than,” “unmitigated,” or “of very thin or transparent texture.”
Rita Ora rocks her typically edgy style in floaty sheer gown with staggering ankle boots as she steps out in London
Balance and sheer talent at the root of tight selection calls – Cullen
Was It Yahoo’s Sheer Size — or Lapsed Security — That Made It a Target for Hackers?
Although less common, sheer may also be used as a noun referring to “a turn, deviation, or change in a course as of a ship” or as an adverb meaning “in a complete manner” or “straight up or down without a break.”
Now that you have learned their different uses and meanings, it would be easier for you to determine whether to use shear or sheer in your sentence. Remember that if it has something to do with cutting, the term to use would be shear. Otherwise, sheer would be the appropriate term.