The Collaborative International Dictionary
Imbittering
Imbitter \Im*bit"ter\, v. t. [imp. & p. p. Imbittered; p. pr. & vb. n. Imbittering.] [Pref. im- in + bitter. Cf. Embitter.] [Written also embitter.] To make bitter; hence, to make distressing or more distressing; to make sad, morose, sour, or malignant.
Is there anything that more imbitters the enjoyment of
this life than shame?
--South.
Imbittered against each other by former contests.
--Bancroft.
Wiktionary
imbittering
vb. (present participle of imbitter English)
Usage examples of "imbittering".
But now her judgment, instead of being controlled by duteous devotion, was made active by the imbittering discovery that in her past union there had lurked the hidden alienation of secrecy and suspicion.