Abc

A for Arduino

B for Beginning

C for Caliber

D for Duration

E for Extent

F for Far

G for Geometry

H for Hand

I for Imperial

J for Job

K for Keep at arm's length

L for Life

M for Meter

N for Normalization

O for One

P for Pascal

Q for Quantity

R for Range

S for Segment

T for Time

U for Unit

V for Vector

W for Wavelength

Y for Yard

Z for Z-axis