"a flat strip," also "something that binds," represents a merger of two words, ultimately from the same source. In the sense "that by which someone or something is bound," it is attested from 1126, from O.N.
band "thin strip that ties or constrains," from P.Gmc.
*bindan (related to Mod.Eng.
bend and
bind), from PIE
*bendh- "to bind" (cf. Goth
bandi "that which binds; Skt.
bandhah "a tying, bandage," source of
bandana; M.Ir.
bainna "bracelet"). Most of the fig. senses of this word have passed into
bond (q.v.), which originally was a phonetic variant of
band. The meaning "a flat strip" (c.1394) is from O.Fr.
bande "strip, edge, side," via O.N.Fr.
bende, from O.H.G.
binda, from P.Gmc.
*bindan (see above). In M.E., this was distinguished by the spelling
bande, but since the loss of the final
-e- the words have fully merged. Meaning "broad stripe of color" is from 1470; the electronics sense of "range of frequencies or wavelengths" is from 1922. The O.N.Fr. form was retained in heraldic
bend.