Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
one-sidedly is an adverb meaning "in a unilateral manner; by means of one part or party". It carries one recorded sense.
in a unilateral manner; by means of one part or party
“they worked out an agreement unilaterally”
Definitions, synonyms and semantic relations for one-sidedly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. .