Of, pertaining to, or as if using parentheses(adjective)
That digresses; discursive or rambling(adjective)
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Use "parenthetic" in a sentence
"While analogical change within the numeral set is common and possible in general, it doesn't appear probable here when Starostin's typically "parenthetic" *ŋi̯u "3" has not been demonstrated with regular sound correspondences using a competently reconstructed phonology that doesn't violate phonemic markedness at every turn."
"In it the second Rhyming Doublet is divided by a kind of parenthetic Rhythmic Solitaire."
"Every time I see an article about this heavily buzzed flick (or in this case NOT about ...), the author just HAS to drop a parenthetic snark to show everyone that he/she has an opinion."