the word 'treat' entered english in the 13th century from the old french 'traitier', meaning "to deal with, negotiate, or handle". this old french term itself evolved from the latin 'tractare', a frequentative form of 'trahere' (to draw, pull, drag). the core semantic thread from latin is the idea of "handling" or "managing" something, which involved drawing it towards oneself for attention. over time, the meaning in english broadened from the act of negotiation or handling to encompass specific modes of handling: behaving towards someone, providing medical care, applying a process, and finally, providing a special gift or entertainment—all nuanced forms of "dealing with" a person or thing.

the word 'treat' is a simplex word derived as a whole from a latin root via old french. it is not productively formed from smaller, recognizable english morphemes in its current spelling.