Ionic meter is a classical metrical pattern made of four syllables in each foot. In the greater Ionic pattern, two long syllables come first followed by two short ones; in the lesser Ionic, two short syllables come first followed by two long ones. In English discussions, these patterns are often described loosely with stressed and unstressed syllables, though the original system is based on syllable length.
Example
Great-er Io-nic: DA DA da da
Less-er Io-nic: da da DA DA