All 3 Uses

allege
in
Frankenstein - 1831 version
(Auto-generated)

Clerval, whose eyes and feelings were always quick in discerning the sensations of others, declined the subject, alleging, in excuse, his total ignorance; and the conversation took a more general turn.†
p. 69.5 *

alleging = claiming
The injustice of his sentence was very flagrant; all Paris was indignant; and it was judged that his religion and wealth rather than the crime alleged against him had been the cause of his condemnation.†
p. 125.8

alleged = said
I often refused to accompany him, alleging another engagement, that I might remain alone.†
p. 164.2

alleging = claiming

Definitions:

(1) (allege)
claim

(In law, this is something that is said and is in need of proof or disproof.)
(2) (meaning too rare to warrant focus)