1. (noun) the elementary stages of any subject (usually plural)

• abc
• abc's
• abcs
• alphabet
• first principle
• first rudiment

1. (noun) the elementary stages of any subject (usually plural)

• basic principle
• basics
• bedrock
• fundamental principle
• fundamentals

2. (noun) the remains of a body part that was functional at an earlier stage of life

• body part

1. (noun) the remains of a body part that was functional at an earlier stage of life

• rudimentary
• rudimentary
• vestigial