expression, ichidan verb
get up; rise from one's seat
Literally 'to lift the portable shrine', but idiomatically means to stand up or get moving, often after being seated for a while. Casual and somewhat old-fashioned.
そろそろみこしを上げて、帰りましょうか。
Shall we get up and head home soon?
expression, ichidan verb
get started; set to work; go into action
Figurative extension: to finally start doing something after procrastinating or hesitating. Often used when someone is slow to begin a task.
いつまでも悩んでいないで、そろそろみこしを上げて仕事に取りかかろう。
Stop worrying forever and let's finally get started on the work.