A particular rhythmic arrangement of syllabic feet in a line, or a particular rhythmic arrangement of stanzas or strophes, based upon their kind and number. There are four types of metrical systems: quantitative meter, syllabic meter, accentual meter, and accentual-syllabic meter. Quantitative meter depends on the length and number of syllables used in classical and Sanskrit verse. Syllabic meter is used in most Romance languages, in which there is a fixed number of syllables with varying accents. Accentual meter is the form of Old English and most Germanic versification, in which the number of accented syllables determines the basic metric unit. Accentual-syllabic meter is the form used in most English poetry, in which both the number of accents and the number of syllables are measured. Meter is based on units (called feet), with each foot usually being a set relationship between one accented syllable and one or two unaccented syllables. The four most common feet in English verse are the "iamb", "trochee", "anapest", and "dactyl"; with variations, such as the "spondee" and "pyrrhic", occasionally occurring. Verse lines are named according to the type of foot they contain, and the number of feet in the line. See accent, foot, scansion, prosody, rhyme, caesura, verse, poetry.