Definition of "so much as"

“Well, she seems to have lost all interest in the horses. For a week now she has driven past the stables with never so much as ‘good morning’!”

1927 March 5, Arthur Conan Doyle, “The Adventure of Shoscombe Old Place”, in The Case-Book of Sherlock Holmes, London: John Murray, […], published June 1927 (May 1952 printing), page 280