[机] 凹口车床

Gap \Gap\ (g[a^]p), n. [OE. gap; cf. Icel. gap an empty space,
Sw. gap mouth, breach, abyss, Dan. gab mouth, opening, AS.
geap expanse; as adj., wide, spacious. See {Gape}.]
1. An opening in anything made by breaking or parting; as, a
gap in a fence; an opening for a passage or entrance; an
opening which implies a breach or defect; a vacant space
or time; a hiatus; a mountain pass.

Miseries ensued by the opening of that gap.
--Knolles.

It would make a great gap in your own honor. --Shak.

2. (A["e]ronautics) The vertical distance between two
superposed surfaces, esp. in a biplane.
[Webster 1913 Suppl.]

{Gap lathe} (Mach.), a turning lathe with a deep notch in the
bed to admit of turning a short object of large diameter.


{To stand in the gap}, to expose one's self for the
protection of something; to make defense against any
assailing danger; to take the place of a fallen defender
or supporter.

{To stop a gap}, to secure a weak point; to repair a defect.