一大 (いちだい, ichidai) Japanese meaning: one large | KotomoraThe discovery caused a great sensation in the scientific community.
He made a major decision and went to study abroad.
Usage patterns
一大〈事〉となるto become a major ~ (event, incident, etc.)
The discovery became a major event in the scientific world.
一大〈物〉を巻き起こすto spark a huge ~ (boom, sensation, etc.)
That movie sparked a huge boom.
一大〈事〉に成長するto grow into a major ~ (industry, undertaking, etc.)
This field grew into a major industry.
機
major turning point; significant turning point
crushing blow; heavy blow; hard blow