tear / tier 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. 👇
tear: (noun) a drop of the clear salty saline solution secreted by the lacrimal glands. (noun) the act of tearing. (verb) separate or cause to separate abruptly. (verb) to separate or be separated by force. (verb) move quickly and violently. (verb) fill with tears or shed tears.
tier: (noun) any one of two or more competitors who tie one another. (noun) a worker who ties something. (noun) something that is used for tying. (noun) one of two or more layers one atop another.
tear: t·EH·r
tier: t·IY·r
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)