"of or relating to dialect, of the nature of a dialect," 1819, from dialect + -al (1). Related: Dialectally.
Entries linking to dialectal
dialect n.
1570s, "language, speech, mode of speech," especially "form of speech of a region or group, idiom of a locality or class" as distinguished from the general accepted literary language, also "one of a number of related modes of speech regarded as descended from a common origin," from French dialecte, from Latin dialectus "local language, way of speaking, conversation," from Greek dialektos "talk, conversation, speech;" also "the language of a country, dialect," from dialegesthai "converse with each other, discuss, argue," from dia "across, between" (see dia-) + legein "speak" from PIE root *leg- (1) "to collect, gather," with derivatives meaning "to speak (to 'pick out words')").
-al 1
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).