Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
left-hander is a noun meaning "a baseball pitcher who throws the ball with the left hand". It carries 2 recorded senses.
a baseball pitcher who throws the ball with the left hand
a person who uses the left hand with greater skill than the right
“their pitcher was a southpaw”
Definitions, synonyms and semantic relations for left-hander come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.