MEANING: noun: 1. A feather or a wing, especially the terminal segment of a wing.
2. A small cogwheel engaging with a larger wheel or a rack.
verb tr.: 1. To cut or bind the wing of a bird.
2. To bind, restrain, shackle, etc.

ETYMOLOGY: For noun 2: From French pignon (cogwheel), from Latin pecten (comb), from pectere (to comb).
For the rest: From French pignon (pinion), from Latin pinna (feather, wing, fin).
Earliest documented use: For noun: 1400; for verb: 1556.

NOTES: According to one website, “The raven has five pinions in each wing and the crow has six. So the true difference between the two is a matter of a pinion!”

pH-IN-ION - determining the acidity of a charged particle

PI? NON - Is pi the 15th letter of the Greek alphabet? (Vraiment, c'est le seizième.)

PIG ION - what the Fourth Little Pig built his Boston house of