the word 'toaster' is a straightforward agent noun formation in english. its core, 'toast', entered the language from the old french verb 'toster', meaning 'to roast or grill', which itself derives from the latin participle 'tostus' (parched, roasted). the latin term traces back to the verb 'torrēre' (to parch, scorch, burn), a common proto-indo-european root related to drying or burning. the suffix '-er', of germanic origin, is one of english's most productive agentive suffixes, attached to verbs to denote 'one who does' or 'that which does'. thus, the literal construction 'one who/that which toasts' perfectly captures both modern meanings: the appliance that performs the toasting action and the person who proposes a drink in honor of someone, the latter sense arising from the 18th-century practice of flavoring drinks with spiced toast.

Structure: toast + er toast (from latin tostus, meaning 'parched, roasted', via old french toster; functions as the base verb/object) + er (from old english -ere, an agent noun suffix indicating a person or thing that performs an action; functions as a derivational suffix)