"pertaining to anecdotes, of the nature of an anecdote," 1794, from anecdote + -al (1). Related: Anecdotally. Anecdotical is attested from 1744.
Entries linking to anecdotal
anecdote n.
1670s, "secret or private stories," from French anecdote (17c.) or directly from Medieval Latin anecdota, from Greek anekdota "things unpublished," neuter plural of anekdotos, from an- "not" (see an- (1)) + ekdotos "published," from ek- "out" (see ex-) + didonai "to give" (from PIE root *do- "to give").
Procopius' 6c. Anecdota, unpublished memoirs of Emperor Justinian full of court gossip, gave the word a sense of "revelation of secrets," which decayed in English to "brief, amusing story" (1761).
-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)).