Ma'anar ƙamus na "condenser" na'ura ce da ke adana cajin lantarki ta hanyar tara cajin da aka saba akan madugu guda biyu masu daidaitawa da kayan wutan lantarki. Haka kuma an fi saninsa da capacitor. Ƙarfin capacitor don adana cajin lantarki ana kiransa capacitance, wanda ake auna shi da raka'a na farads. Ana amfani da capacitors a cikin kewayon lantarki da na lantarki, kamar kayan wuta, kayan aikin sauti, da tsarin sadarwa.