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"
that time; that moment; "we will arrive before then"; "we were friends from then on"
subsequently or soon afterward (often used as sentence connectors); "then he left"; "go left first, then right"; "first came lightning, then thunder"; "we watched the late movie and then went to bed"; "and so home and to bed"
at that time; "I was young then"; "prices were lower back then"; "science as it was then taught"
in that case or as a consequence; "if he didn't take it, then who did?"; "keep it then if you want to"; "the case, then, is closed"; "you've made up your mind then?"; "then you'll be rich"
lengthen in time; cause to be or last longer; "We prolonged our stay"; "She extended her visit by another day"; "The meeting was drawn out until midnight"
lengthen or extend in duration or space; "We sustained the diplomatic negotiations as long as possible"; "prolong the treatment of the patient"; "keep up the good work"