Mid 19th century; earliest use found in Salem (Massachusetts) Gazette. Origin uncertain. Apparently a rhyming compound, in which the first element apparently ultimately reflects classical Latin locus, and the second element classical Latin focus; if so, it is unclear whether the intended meaning is approximately ‘fire in place’ or ‘in place of fire’ (i.e. fire does not need to be introduced from elsewhere), or whether the word arises from a misapprehension of locomotive as literally meaning ‘self-moving’, hence this word might have been envisaged as very approximately ‘self-igniting’.