Exact historical dictionary sense
Mother in Webster's 1913 dictionary
The 1913 record labels mother as noun. Its source-bounded etymology and selected historical definition appear below.
WEBSTER 1913noun
Mother
[Akin to D. modder mud, G. moder mold, mud, Dan. mudder mud, and to E. mud. See Mud.]
Cross-verified historical senseHeadwordmother
Part of speechnoun
Historical etymology[Akin to D. modder mud, G. moder mold, mud, Dan. mudder mud, and to E. mud. See Mud.]
Selected historical definitionA film or membrane which is developed on the surface of fermented alcoholic liquids, such as vinegar, wine, etc., and acts as a means of conveying the oxygen of the air to the alcohol and other combustible principles of the liquid, thus leading to their oxidation.
Signed record IDwebster1913-mother-noun-37d02e0ebabc
Source locatorCIDE.M, paragraph 10057; Gutenberg eBook 665
Quick answer
In Webster's Revised Unabridged Dictionary (1913), "mother" is labeled noun. Its etymology is recorded as: "[Akin to D. modder mud, G. moder mold, mud, Dan. mudder mud, and to E. mud. See Mud.]" The selected historical definition says: "A film or membrane which is developed on the surface of fermented alcoholic liquids, such as vinegar, wine, etc., and acts as a means of conveying the oxygen of the air to the alcohol and other combustible principles of the liquid, thus leading to their oxidation."