bat·ten 2 
(bătn)
(bătn)n.
1. Nautical
a. One of several flexible strips of wood or plastic placed in pockets at the outer edge of a sail to keep it flat.
b. A narrow strip of wood used to fasten down the edges of the material that covers hatches in foul weather.
2. A narrow strip of wood used in construction, especially to cover a seam between boards, as flooring material, or as a lath.
3.
a. The heavy swinging bar on a loom that holds the reed and is pulled forward to pack down the weft.
b. A flat stick used in weaving by hand to separate the upper and lower threads of the warp and to tighten the weft.
tr.v. bat·tened, bat·ten·ing, bat·tens
Idiom: Nautical To furnish, fasten, or secure with battens: battened down the hatch during the storm.
batten down the hatches
To prepare for an imminent disaster or emergency.
[Alteration of Middle English batent, finished board or bar of wood, from Old French batant, wooden strip, clapper, from present participle of batre, to beat; see BATTER1. Noun, sense 3a and b, from French batant, from Old French.]