Loathsomeness is a synonym of abomination.

As nouns the difference between loathsomeness and abomination

is that loathsomeness is the property or nature that gives rise to revulsion, that inspires loathing while abomination is an abominable act; a disgusting vice; a despicable habit {{defdate|first attested around 1150 to 1350}}{{reference-book | last =| first = | authorlink = | coauthors = | editor =brown, lesley | others = | title = the shorter oxford english dictionary | origdate = | origyear = 1933| origmonth = | url = | format = | accessdate = | accessyear = | accessmonth = | edition = 5th | date = | year =2003| month = | publisher =oxford university press | location =oxford, uk | language = | id = | doi = | isbn =978-0-19-860575-7 | lccn = | ol = | pages =6| chapter = | chapterurl = | quote =}}.