Fay \Fay\ (f[=a]), v. t. [imp. & p. p. {fayed}; p. pr. & vb. n. {Faying}.] [OE. feien, v.t. & i., AS. f[=e]gan to join, unite; akin to OS. f[=o]gian, D. voegen, OHG. fuogen, G. f["u]gen, Sw. foga. See {Fair}, and cf. {Fadge}.] (Shipbuilding) To fit; to join; to unite closely, as two pieces of wood, so as to make the surface fit together.