Wiktionary
unmetrical
a. Not written in meter
Usage examples of "unmetrical".
It is indeed a very subtle pleasure to perceive the effect of lines which are unmetrical superficially but which yet confine themselves to a fixed structure below, by varying the stresses and compensating for them.
Hence lines which taken singly seem almost unmetrical, in combination with their associates appear indispensable parts of the general harmony.