add by mixing or blending on or attaching; "work in the butter and the dough will get the right consistency"; "In his speech, the presidential candidate worked in a lot of learned words"
a splendid assemblage (especially of famous people)
(astronomy) a collection of star systems; any of the billions of systems each having many stars and nebulae and dust; "`extragalactic nebula' is a former name for `galaxy'"