The meaning of "span" that belongs to horses
Solution 1:
It is an old usage that refers to a pair of horses driven together:
Span:
- (obsolete) A pair of horses or other animals driven together; usually, such a pair of horses when similar in color, form, and action.
Wiktionary
Origin:
- "two animals driven together," 1769, American English, from Dutch span, from spannen "to stretch or yoke," from Middle Dutch spannan. Also used in South African English.
Etymonline
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