Definition of "pleonasm"

St. Jerome and St. Augustine are both sparing in the employment of the device of pleonasm.

1939, John Nicholas Hritzu, The Style of the Letters of St. Jerome, Catholic University of America Press, page 5

Indeed, pleonasm, the use of superfluous or redundant words, is only part of the broader features of that style, the expressions of which have been so thoroughly analyzed by Franz Neirynck2 and which for convenience will here be referred to as "dualisms."

1989, Harold Riley, The Making of Mark: An Exploration, Mercer University Press, page 219

My salvation is in my Saviour who saveth me hence the redundancy and pleonasm of my asseveration.

1993, Anthony Burgess, A Dead Man in Deptford