To well (up/forth), spring (up/forth) (continually).
To be rolling, be hilly.
(''+ elative'') To evolve from, stem from, (be) originate(d) in (continually — or in a manner that irritates the speaker).
''Hänen päästään kumpuilee jatkuvasti uusia ideoita.''
''New ideas keep coming out of his/her head.''