Anceps
In languages with quantitative poetic metres, such as Ancient Greek, Latin, Arabic, Sanskrit, and classical Persian, an anceps (plural ancipitia or (syllabae) ancipites) is a position in a metrical pattern which can be filled by either a long or a short syllable. In general, anceps syllables in words, such as the first syllable of the Greek words Ἄρης Árēs (the Greek god of war) or πικρός pikrós "bitter", which can be treated by poets as either long or short, can be distinguished from anceps elements or positions in a metrical pattern, which are positions where either a long syllable or a short syllable can be used.