Definition of muscularize in English:

muscularize

Pronunciation /ˈmʌskjʊlərʌɪz/

verb

(also muscularise)
  • 1 rare To become muscular; to put on muscle.

  • 2To make muscular.

Origin

Early 19th century; earliest use found in Samuel Taylor Coleridge (1772–1834), poet, critic, and philosopher. From muscular + -ize.