More on Spear-half from Infoplease:

• Spear-half - Spear-half The male line. The female line was called by the Anglo-Saxons the Spindle-half (q.v.). ...
• Spindle-half - Spindle-half The female line. A Saxon term. The spindle was the pin on which the thread was wound ...
• Dictionary of Phrase and Fable: S - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "S"