Cikin yanayin yanayi, gajimare shine aerosol wanda ya ƙunshi ɗigon ɗigon ruwan ɗigon ruwa na dindindin, kristal mai daskarewa, ko wasu barbashi da aka dakatar a cikin yanayin jikin duniya ko makamancin haka. Ruwa ko wasu sunadarai daban -daban na iya tsara ɗigon ruwa da lu'ulu'u. A doron ƙasa, ana samun gajimare sakamakon ɗimbin iska lokacin da aka sanyaya shi zuwa raɓa, ko kuma lokacin da ya sami isasshen danshi (galibi a cikin yanayin tururin ruwa ) daga wani maƙwabcin kusa don ɗaga alamar raɓa ga yanayin zazzabi. Suna gani a Duniya ta homosphere, wanda ya hada da troposphere, stratosphere, kuma mesosphere. Nephology ne kimiyya na girgije, wanda aka Kanmu a cikin girgije kimiyyar lissafi reshen meteorology. Akwai hanyoyi guda biyu na ba da suna gajimare a cikin sahun su na sararin samaniya, Latin da na kowa. Ana iya samun asalin kalmar "girgije" a cikin tsoffin kalmomin Ingilishi clud ko clod, ma'ana tudu ko taro na dutse. A kusa da farkon karni na 13, an fara amfani da kalmar a matsayin kwatancen girgije na ruwan sama, saboda kamanceceniya a cikin bayyanar tsakanin babban dutsen da girgije mai tarin yawa.