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Webster 1913 Edition
Lath
Lath
,Noun.
pl. 
Laths 
(#)
. [OE. 
laththe
, latthe
, latte
, AS. lætta
; akin to D. lat
, G. latte
, OHG. latta
; cf. W. llath 
a rod, staff, yard. Cf. Lattice
, Latten
.] A thin, narrow strip of wood, nailed to the rafters, studs, or floor beams of a building, for the purpose of supporting the tiles, plastering, etc. A corrugated metallic strip or plate is sometimes used. 
Lath brick
, a long, slender brick, used in making the floor on which malt is placed in the drying kiln. 
Lath nail 
a slender nail for fastening laths.
 Lath
,Verb.
 T.
 [
imp. & p. p. 
Lathed
; p. pr. & vb. n. 
Lathing
.] To cover or line with laths. 
Webster 1828 Edition
Lath
L'ATH
, n.1.
  A thin, narrow board or slip of wood nailed to the rafters of a building to support the tiles or covering.2.
  A thin narrow slip of wood nailed to the studs, to support the plastering.L'ATH
,Verb.
T.
  L'ATH
,Noun.
  In some parts of England, a part or division of a county.  Spenser, Spelman and Blackstone do not agree in their accounts of the lath; but according to the laws of Edward the Confessor, the lath, in some counties, answered to the trithing or third part of a county in others.