Billion vs. Pillion — What's the Difference?

A billion is a number with two distinct definitions: 1,000,000,000, i.e. one thousand million, or 109 (ten to the ninth power), as defined on the short scale.

A pillion is a secondary pad, cushion, or seat behind the main seat or saddle on a horse, motorcycle, bicycle or moped. A passenger in this seat is said to "ride pillion".

The cardinal number equal to 109.

A seat for a passenger behind a motorcyclist.

Chiefly British The cardinal number equal to 1012.

A pad or cushion for an extra rider behind the saddle on a horse or motorcycle.

An indefinitely large number.

A bicycle or motorcycle saddle.

A thousand million ([https://en.wikipedia.org/wiki/Long_and_short_scales#Comparison logic: 1,000 × 1,000^2]): 1 followed by nine zeros, 10⁹; a milliard

A pad behind the saddle of a horse for a second rider.

A million million ([https://en.wikipedia.org/wiki/Long_and_short_scales#Comparison logic: 1,000,000^2]): a 1 followed by twelve zeros; 10¹²

(motorcycling) A similar second saddle on a motorcycle for a passenger.

An unspecified very large number.

The person riding in the pillion.

According to the French and American method of numeration, a thousand millions, or 1,000,000,000; according to the English method, a million millions, or 1,000,000,000,000. See Numeration.

The cushion of a saddle.

The number that is represented as a one followed by 12 zeros; in the United Kingdom the usage followed in the United States is frequently seen

Riding behind the driving rider, as when positioned on the rump of a mount.

The number that is represented as a one followed by 9 zeros

To ride on a pillion.

Denoting a quantity consisting of one thousand million items or units in the United States

To put a pillion on a horse.

Denoting a quantity consisting of one million million items or units in Great Britain

A panel or cushion saddle; the under pad or cushion of saddle; esp., a pad or cushion put on behind a man's saddle, on which a woman may ride.

A seat behind the rider of a horse or motorbike etc.