souter.

From Middle Dutch souter (which existed alongside forms such as psalter and seltre), possibly with L-vocalization from Old Dutch psaltere, psaltare, from Latin psalterium (possibly by way of a Proto-West Germanic *psalterī), ultimately from Ancient Greek ψᾰλτήρῐον (psăltḗrĭon). Alternatively, the Middle Dutch forms with L-vocalization (a regular sound found also in e.g. Middle Dutch sout, from Old Dutch *salt) may not represent a Middle Dutch development from Old Dutch but rather a borrowing from Old French forms that feature -aut-, such as sautier. Doublet of psalter, psalterie, and psalterium.