1 A low embankment or ridge on a sand beach, constructed by swash or breaking waves. Weir et al. (2006) Geomorph. 82, 3–4 examine two models of berm development: vertical growth at spring tides or ‘following significant beach cut due to substantial swash overtopping’; and horizontal progradation at neap tides through the formation of a proto-berm, located lower and further seaward of the principal berm.

2 A benchlike remnant of a surface resulting from the interruption of an erosion cycle. Berms may occur naturally in a river channel, or they may be constructed as part of a river restoration.

http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=home.showFile&rep=file&fil=STREAM_Restoration_Techniques_Advice_Note.pdf A colourful and useful example of a berm on European Commission’s Environment site.