His principal reason for making the journey was to visit his family.
Teaching is her principal source of income.
the principal character in the book
➔principallyWORD FOCUS: important WORD FOCUS: important similar words:main, key, chief, principal, leading, vital, crucial, essential, significant not important:unimportant, trivial, minor, irrelevant, insignificant ➔ See alsoimportant
Definition from the Longman Dictionary of Contemporary English Advanced Learner's Dictionary.