Contextual comparative. Modifies another adjective (to which the "so" is a direct anaphoric reference), indicating a greater degree of the quality in question.(adjective)
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Use "more so" in a sentence
"Guided by ancient Jewish and Christian tradition they feel constrained to abide by the explicit titles to the same collections, all the more so because the titles in the Book of Proverbs are manifestly discriminating with respect to authorship, and because the title, "These also are Mishle Shelomoh, which the men of Ezechias, King of Juda, copied out" (xxv, 1), in particular, bears the impress of definiteness and accuracy."
"Even more so than during her travels since leaving the da Vinci less than a week ago, the usually stalwart security chief found herself once again walking wobbly and feeling queasy as the ship sped toward its meeting with Thelkan traders."
"That Tom Bishop had died, and that one never knew for certain what or whom Charity remembered from one day to the next, were an endless source of grief for both their children, but maybe, in some ways, just slightly more so for Matt, who had so fiercely loved the couple who had taken him in and saved his life—and his soul—in so many ways."