The Collaborative International Dictionary of English v.0.48:
Span \Span\, n. [AS. spann; akin to D. span, OHG. spanna, G.
spanne, Icel. sp["o]nn. [root]170. See Span, v. t. ]
1. The space from the thumb to the end of the little finger
when extended; nine inches; eighth of a fathom.
2. Hence, a small space or a brief portion of time.
Yet not to earth's contracted span
Thy goodness let me bound. --Pope.
Life's but a span; I'll every inch enjoy.
3. The spread or extent of an arch between its abutments, or
of a beam, girder, truss, roof, bridge, or the like,
between its supports.
4. (Naut.) A rope having its ends made fast so that a
purchase can be hooked to the bight; also, a rope made
fast in the center so that both ends can be used.
5. [Cf. D. span, Sw. spann, Dan. spaend, G. gespann. See
Span, v. t. ] A pair of horses or other animals driven
together; usually, such a pair of horses when similar in
color, form, and action.
Span blocks (Naut.), blocks at the topmast and
topgallant-mast heads, for the studding-sail halyards.
Span counter, an old English child's game, in which one
throws a counter on the ground, and another tries to hit
it with his counter, or to get his counter so near it that
he can span the space between them, and touch both the
counters. --Halliwell. "Henry V., in whose time boys went
to span counter for French crowns." --Shak.
Span iron (Naut.), a special kind of harpoon, usually
secured just below the gunwale of a whaleboat.
Span roof, a common roof, having two slopes and one ridge,
with eaves on both sides. --Gwilt.
Span shackle (Naut.), a large bolt driven through the
forecastle deck, with a triangular shackle in the head to
receive the heel of the old-fashioned fish davit. --Ham.