Acephalous line

An acephalous or headless line is a line in a poem which does not conform to its accepted metre, due to the first syllable's omission. Acephalous lines are usually deliberate variations in scansion, but this is not always obvious. Famous poems to use such a technique include A.E. Housman's To an Athlete Dying Young. Robert Wallace argues in his Meter in English that the term acephalous line seems "pejorative", as if criticising the poet's violation of scansion, but this view is not widely held among critics.