Dactylic tetrameter is a metre in poetry.[1] It refers to a line consisting of four dactylic feet. "Tetrameter" simply means four poetic feet. Each foot has a stressed syllable followed by two unstressed syllables, the opposite of an anapest, sometimes called antidactylus to reflect this fact.
A dactylic foot is one stressed syllable followed by two unstressed ones:
| DUM | da | da |
A dactylic tetrameter would therefore be:
| DUM | da | da | DUM | da | da | DUM | da | da | DUM | da | da |
Scanning this using an "x" to represent an unstressed syllable and a "/" to represent a stressed syllable would make a dactylic tetrameter like the following:
| / | x | x | / | x | x | / | x | x | / | x | x |
The following lines from The Beatles' "Lucy in the Sky with Diamonds" demonstrate this, the scansion being:
| / | x | x | / | x | x | / | x | x | / | x | x | |
| Pic- | ture | your- | self | in | a | boat | on | a | riv- | er | with |
| / | x | x | / | x | x | / | x | x | / | x | x | |
| tan- | ger- | ine | tree- | ees | and | marm- | a- | lade | skii- | ii- | es |
Another example, from Browning:
| / | x | x | / | x | x | / | x | x | / | x | |
| Just | for | a | hand- | ful | of | sil- | ver | he | left | us! |
| / | x | x | / | x | x | / | x | x | / | x | |
| What | can | I | tell | you | my | bro- | ther | my | kee- | per |
| / | x | x | / | x | x | / | |
| What | can | I | poss- | ib- | ly | say |