Fantôme vs. spectre
The French words 'fantôme' and 'spectre' are both used to describe entities generally recognized as ghosts or spirits. While they are broadly synonymous, there are nuanced differences in their usage and connotations that can be noted through various examples.
Fantôme
The term 'fantôme' typically refers to an apparition or spirit of a dead person, often associated with haunted places. It is the most commonly used term for ghost in French.
Le château est réputé pour être hanté par le fantôme d'une ancienne reine.
(The castle is reputed to be haunted by the ghost of a former queen.)
Certains disent avoir vu un fantôme se promener dans les couloirs la nuit.
(Some say they have seen a ghost wandering the halls at night.)
Le jeune enfant s’est caché sous les draps, persuadé qu’un fantôme était dans sa chambre.
(The young child hid under the sheets, convinced that there was a ghost in his room.)
Spectre
'Spectre' also refers to a ghost but carries a connotation of something broader, like a phantom or a specter including non-human forms. It can also figuratively suggest an idea that haunts or threatens.
Quand j'ai visité les ruines au clair de lune, j'ai cru voir le spectre d'un ancien guerrier.
(When I visited the ruins by moonlight, I thought I saw the specter of an ancient warrior.)
Le spectre de la guerre plane sur le continent.
(The specter of war looms over the continent.)
Il raconte que des spectres apparaissent chaque nuit au bord du lac.
(He says that specters appear every night by the lake's edge.)
Summary
Although 'fantôme' and 'spectre' can both be translated to 'ghost', 'fantôme' is more frequently used to describe the traditional ghostly figure, often with a human origin, whereas 'spectre' can have a broader meaning including less defined shapes and/or figures and is also used metaphorically for non-physical threats or fears.