[Latin adjectival ending -aris.]
Latin word stems that ended in l employed -aris to make their adjectives rather than -alis, the source of our -al1 suffix. As a result, the majority of adjectives in -ar in English have l or ul before the suffix, such as angular, circular, familiar, globular, jocular, polar, regular, similar, singular, and vulgar (see also -ule). Other English adjectives derived from Latin words ending in -aris include columnar, linear, lumbar, lunar, planar, and stellar. Some English adjectives have been formed using -ar that do not have Latin originals in -aris, often being based instead on Latin nouns in -um: curricular, granular, molecular, nuclear, scapular. See also -ary2.