1. the fourth letter of the Greek alphabet (Δ, δ)
2. a triangular area of land formed at the mouth of a river where it splits into smaller streams
3. a change or difference between two values or states
Usage: mathematics; science

Examples

• The Greek letter delta is used in mathematics to represent change.
• The Mississippi River delta is home to many species of wildlife.
• Scientists measured the delta between the two temperature readings.
• The airplane has a delta wing design.
• The Nile delta is one of the most fertile regions in Egypt.
• Calculate the delta of the function over this interval.
• The river delta extends far into the ocean.