Gaslight

[gas-lahyt] /ˈgæsˌlaɪt/

noun
1.
light produced by the combustion of illuminating gas.
2.
a or for producing this kind of light.
adjective
3.
(def 2).
verb (used with object), gaslighted or gaslit, gaslighting.
4.
to cause (a person) to doubt his or her sanity through the use of psychological manipulation:
How do you know if your partner is gaslighting you?
/ˈɡæsˌlaɪt/
noun
1.
a type of lamp in which the illumination is produced by an incandescent mantle heated by a jet of gas
2.
the light produced by such a lamp
verb

to manipulate someone into questioning their own sanity; to subtly drive someone crazy
Word Origin

1956
Usage Note

slang; gaslighting, n

verb

To deceive someone systematically: He set me up and has been gaslighting me

[1950s+; fr the 1944 movie Gaslight, in which a man attempts to drive his wife mad by causing her to mistrust her senses]