Bated here is a contraction of abated through loss of the unstressed first vowel a process called aphesis; it means “reduced, lessened, lowered in force”.    From Wordnik.com.  [Watch This: 44 Inch Chest Official Trailer with Ray Winstone « FirstShowing.net] Reference

Among phonetic changes which occur with more or less regularity are those called aphesis, epenthesis, epithesis, assimilation, dissimilation, and metathesis, convenient terms which are less learned than they appear.    From Wordnik.com.  [The Romance of Names] Reference

There were other charges brought against Cocceius, however, one of which was his distinction between +aphesis hamartiôn+ and +paresis hamartiôn+, by which he held that the former was a complete pardon, but the latter incomplete, and only in force under the old dispensation.    From Wordnik.com.  [History of Rationalism Embracing a Survey of the Present State of Protestant Theology] Reference

When the saint's name begins with a consonant, we get, instead of aphesis, a telescoped pronunciation, e.g. Selinger, St. Leger, Seymour, St. Maur, Sinclair, St. Clair.    From Wordnik.com.  [The Romance of Names] Reference