rail / rayl [reil]
rail – n. & v. – n. – 1. a horizontal bar or series of them; 2. a bird, the corncrake or landrail, or other members of the order rallidae; 3. a protest or complaint; v. – 1. to fasten in a row; 2. to fish with the land line over the edge of a boat; 3. to wander; 4. to complain persistently
rayl – n. – one rayl represents the specific acoustic impedance when a sound pressure of 1 Pa produces a linear velocity of 1 m/s, named after Lord Rayleigh - characteristic impedance or specific acoustic impedance has units of kgm-2s-1 where the value of oc in air at 20oC is 1.21x343 = 415 Rayl