Initially, General Electric gains little twins (6)
I believe the answer is:
gemini
'twins' is the definition.
(twins are the symbol of the star sign Gemini)
'initially general electric gains little' is the wordplay.
'initially' indicates taking the first letters.
'gains' means one lot of letters go next to another.
'little' becomes 'mini' ().
The initial letters of 'general electric' is 'ge'.
'ge'+'mini'='GEMINI'
(Other definitions for gemini that I've seen before include "May person" , "Castor and Pollux constellation" , "Heavenly sign of the Twins" , "lot of stars" , "Third zodiacal sign" .)