The verb 'tease' has a long history in English, tracing back to the Old English 'tǣsan', meaning to pull apart, pluck, or tear. This Old English term is related to similar words in other Germanic languages, such as Middle Dutch 'tēsen'. The original, concrete sense involved the pulling apart of fibers, such as wool or flax, to prepare them for spinning. From this tactile action, the meaning broadened metaphorically to describe the act of pulling someone's emotions or patience apart through persistent annoyance or mockery. Thus, the modern dual meanings—one literal (to disentangle fibers) and one figurative (to provoke or mock)—both logically evolved from this core idea of pulling or picking at something until it separates.

The word 'teased' is the inflected past tense and past participle form of the verb 'tease'. The root 'tease' is considered a simplex unit in modern English. Its core morpheme 'tease-' carries the semantic meaning, and the suffix '-ed' (from Old English '-ode', '-ade', '-ed') is an inflectional suffix indicating past tense or past participle.