the word 'trolley' is a relatively recent english coinage from the early 19th century. its origin is likely dialectal, possibly from the english word 'troll', meaning 'to roll' or 'to move about', which itself has old norse and middle low german roots. the suffix '-ey' or '-y' is a common diminutive or noun-forming ending in english. the term was first applied to a small cart or truck used in mines and later became specifically associated with wheeled baskets and streetcars, the latter due to the trolley pole used to draw current from an overhead wire. its evolution captures the shift from a general term for a rolling vehicle to specific modern applications.

the word 'trolley' is a simplex form. it is not productively composed of smaller, meaningful morphemes in modern english. it functions as a single, unsegmentable unit.